Ruby: Small fix

Author: hmac

ruby/ql/lib/codeql/ruby/frameworks/actioncontroller/Filters.qll

@@ -256,7 +256,7 @@ module Filters {
 
     predicate isPrepended() { call.getMethodName().regexpMatch("^prepend.+$") }
 
-    MethodCallCfgNode getCall() { result = call }
+    FilterCall getCall() { result = call }
 
     FilterKind getKind() { result = kind }