Fix 2 possible NullPointer occurences

marco

2015-10-17 1aec17636d8c548257cb307f8cc1e41354e00421

 src/main/java/com/gitblit/utils/ModelUtils.java

@@ -38,7 +38,7 @@
         userRepoPrefix = Constants.DEFAULT_USER_REPOSITORY_PREFIX;
         return;
      }
		

      String newPrefix = prefix.replace('\\', '/');
      if (prefix.charAt(0) == '/') {
         newPrefix = prefix.substring(1);