Make it work with any version of the JDK. fixes MPJAVA-22.

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@116120 13f79535-47bb-0310-9956-ffa450edef68

java/plugin.jelly

@@ -48,7 +48,6 @@
           excludes="**/package.html"
           debug="${maven.compile.debug}"
           deprecation="${maven.compile.deprecation}"
-          target="${maven.compile.target}"
           optimize="${maven.compile.optimize}">
           <ant:src>
             <ant:path refid="maven.compile.src.set"/>
@@ -116,6 +115,10 @@
           <j:if test="${context.getVariable('maven.compile.source') != null}">
             <ant:setProperty name="source" value="${maven.compile.source}" />
           </j:if>
+
+          <j:if test="${context.getVariable('maven.compile.target') != null}">
+            <ant:setProperty name="target" value="${maven.compile.target}" />
+          </j:if>
           
           <j:if test="${context.getVariable('maven.compile.verbose') != null}">
             <ant:setProperty name="verbose" value="${maven.compile.verbose}" />