rfc3986: don't enforce actions for rules

some users may not care about actions for the top level rules so we
shouldn't enforce them.

rfc3986.rl

@@ -136,5 +136,5 @@
 
     URI = (
         absolute_uri | uri_reference
-    ) >uri_begin %uri_end;
+    );
 }%%

uri.cpp.rl

@@ -65,7 +65,7 @@
 
     include rfc3986 'rfc3986.rl';
 
-    impl := URI
+    impl := URI >uri_begin %uri_end
     %success
     $!failure
     $trace;