Revert "[maven-release-plugin] prepare release maven-compiler-plugin-…

…3.8.1"

This reverts commit e09eb57.

pom.xml

@@ -30,7 +30,7 @@ under the License.
   </parent>
 
   <artifactId>maven-compiler-plugin</artifactId>
-  <version>3.8.1</version>
+  <version>3.8.1-SNAPSHOT</version>
   <packaging>maven-plugin</packaging>
 
   <name>Apache Maven Compiler Plugin</name>
@@ -45,7 +45,7 @@ under the License.
     <connection>scm:git:https://gitbox.apache.org/repos/asf/maven-compiler-plugin.git</connection>
     <developerConnection>scm:git:https://gitbox.apache.org/repos/asf/maven-compiler-plugin.git</developerConnection>
     <url>https://github.com/apache/maven-compiler-plugin/tree/${project.scm.tag}</url>
-    <tag>maven-compiler-plugin-3.8.1</tag>
+    <tag>HEAD</tag>
   </scm>
   <issueManagement>
     <system>JIRA</system>