bootstrap navbar toggle avoid second scrollbar - html

Question

is there a way to avoid the second scrollbar when bootstrap toggle?
cool wood be if there is a trick to avoid it :) thanks at all best would be to increase the height or something like that?
My bootstrap default-nav css code:
#media (max-width: 1200px) {
.navbar-header {
float: none;
}
.navbar-left, .navbar-right {
float: none !important;
}
.navbar-right {
margin-right: 0;
background-color: #2c3e50;
}
.navbar-toggle {
display: block;
float:right;
}
.navbar-collapse {
border-top: 1px solid transparent;
box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1);
background-color: #fff;
text-align: left;
}
.navbar-fixed-top {
top: 0;
border-width: 0 0 1px;
}
.navbar-collapse.collapse {
display: none !important;
background-color: #fff;
text-align: left;
}
.navbar-nav {
float: none !important;
background-color: #fff;
text-align: left;
margin-top: 7.5px;
}
.navbar-nav > ul {
width: 100%;
}
.navbar-nav > li {
float: none;
height: 45px;
line-height: 36px;
}
.navbar-nav > li > a {
padding-top: 10px;
padding-bottom: 10px;
border-right: none;
height: 45px;
line-height: 36px;
}
.navbar-nav .open .dropdown-menu {
display: block;
position: static;
float: none;
width: auto;
margin-top: 0;
background-color: #fff;
border: 0;
-webkit-box-shadow: none;
box-shadow: none;
}
.collapse.in {
display: block !important;
}
}
<div class="container" id="head">
<div id="logo"><a href="?index.php"><img src="include/designs/foekuhei/images/logo.png"
class="img-responsive" alt="Förderkreis für Kultur und Heimatgeschichte e.V. Gottmadingen" /></a></div>
<nav class="navbar navbar-default">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#trebingnav" aria-expanded="false">
<span class="sr-only">Navigation ein-/ausblenden</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
</div>
<div class="collapse navbar-collapse" id="trebingnav">
<ul class="nav navbar-nav">
<li class="Home">Home</li>
<li class="Experimentelle">Experimentelle</li>
<li class="dropdown Veranstaltungen">
<a href="index.php?news" class="dropdown-toggle" data-toggle="dropdown"
role="button" aria-haspopup="true" aria-expanded="false">Veranstaltungen <span class="caret"></span></a>
<ul class="dropdown-menu Verantstaltungen">
<li>Aktuelles Programm</li>
<li>Aktuelles Jahresprogramm</li>
<li>Andere Veranstaltungen</li>
<li>R&uumlckblick</li>
<li>Bildergalerien</li>
</ul>
</li>
<li class="dropdown Wir">
<a href="index.php?vorstand" class="dropdown-toggle" data-toggle="dropdown"
role="button" aria-haspopup="true" aria-expanded="false">&Uumlber uns <span class="caret"></span></a>
<ul class="dropdown-menu">
<li>Vorstand</li>
<li>Ehrungen</li>
<li>Geschichte</li>
<li>Satzung</li>
<li>Links</li>
</ul>
</li>
<li class="Projekte">Projekte</li>
<li class="Tickets">Tickets</li>
<li class="dropdown Mitglied">
<a href="index.php?mitgliedwerden" class="dropdown-toggle" data-toggle="dropdown"
role="button" aria-haspopup="true" aria-expanded="false">Mitglied werden <span class="caret"></span></a>
<ul class="dropdown-menu Mitglied">
<li>Warum beitreten?</li>
<li>Online-Beitritt</li>
</ul>
</li>
<li class="dropdown Kontakt">
<a href="index.php?contact" class="dropdown-toggle" data-toggle="dropdown"
role="button" aria-haspopup="true" aria-expanded="false">Kontakt</a>
<ul class="dropdown-menu">
<li>Kontakt</li>
<li>Anfahrt</li>
</ul>
</li>
<li class="Impressum" >Impressum</li>
</ul>
</div>
</nav>
</div><!-- Close HEAD -->