Handle error when publishing non draft patch set

Trying to publish a non draft patch set with the 'review' SSH command
failed with an 'internal server error'. Now the error is handled and
a proper error message is printed out.

Change-Id: Iad0e923e7e4f30387eff165776231ff32289dd96
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/ReviewCommand.java

@@ -294,6 +294,9 @@ public class ReviewCommand extends BaseCommand {
         case RULE_ERROR:
           errMsg += "rule error";
           break;
+        case NOT_A_DRAFT:
+          errMsg += "change is not a draft";
+          break;
         default:
           errMsg += "failure in review";
       }