imap: Make sure pending input is handled when a pending command has i…

…nput locked.

This hopefully fixes the last assert-crash in client_check_command_hangs()

src/imap/imap-client.c

@@ -856,7 +856,7 @@ static bool client_remove_pending_unambiguity(struct client *client)
 		struct client_command_context *cmd = client->input_lock;
 
 		if (cmd->state != CLIENT_COMMAND_STATE_WAIT_UNAMBIGUITY)
-			return FALSE;
+			return TRUE;
 
 		/* the command is waiting for existing ambiguity causing
 		   commands to finish. */