no need to visit nonexistent source; proxy2 depends on Java v6 so generate classfile for that target

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/proxy/branches/version-2.0-work@1520920 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/asm4/src/main/java/org/apache/commons/proxy2/asm4/ASM4ProxyFactory.java b/asm4/src/main/java/org/apache/commons/proxy2/asm4/ASM4ProxyFactory.java
index 22c74e2..8ad664a 100644
--- a/asm4/src/main/java/org/apache/commons/proxy2/asm4/ASM4ProxyFactory.java
+++ b/asm4/src/main/java/org/apache/commons/proxy2/asm4/ASM4ProxyFactory.java
@@ -128,8 +128,7 @@
                 interfaceNames[i] = anInterface.getName().replace('.', '/');
             }
 
-            cw.visit(V1_5, ACC_PUBLIC + ACC_SUPER, proxyClassFileName, null, classFileName, interfaceNames);
-            cw.visitSource(classFileName + ".java", null);
+            cw.visit(V1_6, ACC_PUBLIC + ACC_SUPER, proxyClassFileName, null, classFileName, interfaceNames);
 
             // push InvocationHandler fields
             cw.visitField(ACC_FINAL + ACC_PRIVATE, HANDLER_NAME, "Ljava/lang/reflect/InvocationHandler;", null, null).visitEnd();