Set the default capture index to 0 instead of -1

git-svn-id: https://emgucv.svn.sourceforge.net/svnroot/emgucv/trunk@291 d7f09016-e345-0410-b530-edf29a71df78

Emgu.CV/Capture/Capture.cs

@@ -80,7 +80,7 @@ namespace Emgu.CV
 
       ///<summary> Create a capture using the default camera </summary>
       public Capture()
-         : this(-1)
+         : this(0)
       {
       }