take into account slot when merging module content (copied from core)

Author: aloubyansky

patch-gen/src/main/java/org/jboss/as/patching/generator/PatchGenerator.java

@@ -41,7 +41,6 @@
 import org.jboss.as.patching.ZipUtils;
 import org.jboss.as.patching.logging.PatchLogger;
 import org.jboss.as.patching.metadata.Patch;
-import org.jboss.as.patching.metadata.PatchMerger;
 import org.jboss.as.version.ProductConfig;
 import org.jboss.modules.Module;