Revert "[maven-release-plugin] prepare release v2.10.0"

This reverts commit b5e5e8a.

Author: truthbk

pom.xml

@@ -5,7 +5,7 @@
   <artifactId>java-dogstatsd-client</artifactId>
   <packaging>jar</packaging>
   <name>java-dogstatsd-client</name>
-  <version>2.10.0</version>
+  <version>2.9.1-SNAPSHOT</version>
   <description>A tiny library allowing Java applications to communicate with DataDog statsd instances easily.</description>
   <url>https://github.com/DataDog/java-dogstatsd-client</url>
 
@@ -34,7 +34,7 @@
     <url>https://github.com/DataDog/java-dogstatsd-client</url>
     <connection>scm:git:git://github.com/DataDog/java-dogstatsd-client.git</connection>
     <developerConnection>scm:git:[email protected]:Datadog/java-dogstatsd-client.git</developerConnection>
-    <tag>v2.10.0</tag>
+    <tag>v2.9.0</tag>
   </scm>
 
   <developers>