test: replication/misc cleanup box.cfg.replication

In patch c6bea65f I
added a bug - replication/misc leaves a bad value in
box.cfg.replication. Before that patch the test was
resetting this to empty replication. In my patch I
forgot about that, and left there the value

    {box.cfg.listen, "12345"}

This patch cleans it up.

Follow up #3760

test/replication/misc.result

@@ -842,7 +842,7 @@ box.info.status
 - running
 ...
 box.cfg{                                                        \
-    replication = replication,                                  \
+    replication = {},                                           \
     replication_connect_quorum = replication_connect_quorum,    \
     replication_connect_timeout = replication_connect_timeout   \
 }

test/replication/misc.test.lua

@@ -342,7 +342,7 @@ box.cfg{                                                        \
 box.cfg{replication = {'localhost:12345'}}
 box.info.status
 box.cfg{                                                        \
-    replication = replication,                                  \
+    replication = {},                                           \
     replication_connect_quorum = replication_connect_quorum,    \
     replication_connect_timeout = replication_connect_timeout   \
 }