ZmtLaunchPlugin.java: rolled back last commit

        being indifferent about version leads to a failed resolve

src/main/groovy/de/zmt/gradle/ZmtLaunchPlugin.groovy

@@ -57,7 +57,7 @@ public class ZmtLaunchPlugin implements Plugin<Project> {
         else {
             // add launcher dependency and make it an application
             project.dependencies {
-                runtime 'de.zmt:zmt-launcher'
+                runtime 'de.zmt:zmt-launcher:latest.release'
             }
             configure(project, MAKE_APPLICATION)
         }