Address a small but clear bug in detector logic

git-svn-id: https://zxing.googlecode.com/svn/trunk@678 59b500cc-1b3d-0410-9834-0bbf25fbcc57

core/src/com/google/zxing/datamatrix/detector/Detector.java

@@ -287,6 +287,7 @@ public final class Detector {
         }
       }
     }
+    start++;
 
     // Then try right/down
     int end = center;
@@ -305,6 +306,7 @@ public final class Detector {
         }
       }
     }
+    end--;
 
     if (end > start) {
       return new int[] { start, end };