Fixed issue with nav height

Closes #35

Author: iamphill

bower.json

@@ -1,6 +1,6 @@
 {
   "name": "bootstrap-offcanvas",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "authors": [
     "Phil Hughes <me@iamphill.com>"
   ],

dist/js/bootstrap.offcanvas.js

@@ -1,6 +1,6 @@
 {
   "name": "offcanvas-bootstrap",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "author": {
     "name": "Phil Hughes",
     "url": "http://www.iamphill.com"

dist/js/bootstrap.offcanvas.min.js

@@ -51,8 +51,9 @@
         _touchStart: (e) =>
             @startX = e.originalEvent.touches[0].pageX
 
-            # Change the height of the offcanvas on touch start
-            @element.height $(window).outerHeight()
+            if @element.is '.in'
+                # Change the height of the offcanvas on touch start
+                @element.height $(window).outerHeight()
 
         #   Private: Touch move
         #