compilerplugins: the useuniqueptr clang plugin test fails on 5.0.1

I'm not sure what is the first version that passes it, let's go with 6.0
for now.

Change-Id: I7a150fbc2a722a6a47d91de4b00893303add5cc8

compilerplugins/clang/test/useuniqueptr.cxx

@@ -278,7 +278,7 @@ class Foo23
     }
 };
 
-#if CLANG_VERSION >= 50000
+#if CLANG_VERSION >= 60000
 class Foo24
 {
     typedef std::vector<int*> HTMLAttrs;