Build with API version 2.9.3

Version 2.9.3 is not the latest version, but for some reason 2.9.4
is not available on Maven Central.

Also make the project version same as the API version.

Change-Id: I8f923573122b8a45cf97c6eb42abdfe81dc20e5c
diff --git a/pom.xml b/pom.xml
index b3d3fc8..c59c1fa 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,12 +21,12 @@
   <groupId>com.google.gerrit</groupId>
   <artifactId>project-download-commands</artifactId>
   <packaging>jar</packaging>
-  <version>1.0-SNAPSHOT</version>
+  <version>2.9.3</version>
   <name>project-download-commands</name>
 
   <properties>
     <Gerrit-ApiType>plugin</Gerrit-ApiType>
-    <Gerrit-ApiVersion>2.9</Gerrit-ApiVersion>
+    <Gerrit-ApiVersion>${project.version}</Gerrit-ApiVersion>
   </properties>
 
   <build>