Fix 2 possible NullPointer occurences

marco

2015-10-17 1aec17636d8c548257cb307f8cc1e41354e00421

 src/main/java/com/gitblit/tickets/QueryBuilder.java

@@ -201,6 +201,12 @@
            q = q.substring(1, q.length() - 1);
         }
      }
      if (q.startsWith("AND ")) {
         q = q.substring(3).trim();
      }
      if (q.startsWith("OR ")) {
         q = q.substring(2).trim();
      }
      return q;
   }