Set stable-2.9 to the latest Gerrit 2.9.3 release

Change-Id: I38d6e8dcd599cddfeb023f885e4b69dfe234e9a3
diff --git a/pom.xml b/pom.xml
index 77182c6..b91c03d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.googlesource.gerrit.plugins.its</groupId>
     <artifactId>its-base-parent</artifactId>
-    <version>2.9-SNAPSHOT</version>
+    <version>2.9.3</version>
   </parent>
   <artifactId>its-jira</artifactId>
   <packaging>jar</packaging>