Test bug introduced by #2090

[guilhermelawless]

#2090

nano-node/nano/rpc_test/rpc.cpp

Lines 6400 to 6401 in a54f292

	std::mutex mutex;
	std::unique_lock<std::mutex> lock (mutex);

nano-node/nano/node/active_transactions.cpp

Line 619 in a54f292

assert (lock_a.mutex () == &mutex && lock_a.owns_lock ());

These two blocks are incompatible (I probably forgot to test in Debug, sorry). Would send a fix but not sure how to escape this without removing the assert