fix snapshot url

plugin.xml

@@ -4,7 +4,7 @@
 	<property name="target.dir" value="${basedir}/target/plugins" />
 
 	<!-- Maven Repository -->
-	<property name="maven.snapshot.repo.url" value="https://oss.sonatype.org/content/repositories/releases" />
+	<property name="maven.snapshot.repo.url" value="https://oss.sonatype.org/content/repositories/snapshots" />
 	<property name="maven.release.repo.url" value="http://central.maven.org/maven2" />
 
 	<target name="install.plugins">