Move reviewDb declaration

We move the declaration of reviewDb into the try/catch block, to make
it more explicit that it only gets used inside that block.

Change-Id: I1da417a87ec009eb024743871328fc270f4c9448

src/main/java/com/googlesource/gerrit/plugins/reviewersbyblame/ChangeUpdatedListener.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewersbyblame/ChangeUpdatedListener.java b/src/main/java/com/googlesource/gerrit/plugins/reviewersbyblame/ChangeUpdatedListener.java
index c352eca..0ce77a1 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewersbyblame/ChangeUpdatedListener.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewersbyblame/ChangeUpdatedListener.java
@@ -111,11 +111,10 @@
       return;
     }
 
-    final ReviewDb reviewDb;
     final RevWalk rw = new RevWalk(git);
 
     try {
-      reviewDb = schemaFactory.open();
+      final ReviewDb reviewDb = schemaFactory.open();
       try {
         Change.Id changeId = new Change.Id(Integer.parseInt(e.change.number));
         PatchSet.Id psId = new PatchSet.Id(changeId, Integer.parseInt(e.patchSet.number));