Trim RPC command table

- invalidateblock and reconsiderblock were defined doubly
- remove no-longer-used threadSafe, as locks have been pushed down

src/rpcserver.h

@@ -98,7 +98,6 @@ public:
     std::string name;
     rpcfn_type actor;
     bool okSafeMode;
-    bool threadSafe;
     bool reqWallet;
 };