test: add testcase of muti-replica mnode

tests/script/jenkins/basic.txt

@@ -133,5 +133,6 @@
 ./test.sh -f tsim/sync/3Replica5VgElect.sim
 ./test.sh -f tsim/sync/oneReplica1VgElect.sim
 ./test.sh -f tsim/sync/oneReplica5VgElect.sim
+./test.sh -f tsim/sync/3Replica5VgElect3mnode.sim
 
 #======================b1-end===============

tests/script/tsim/sync/3Replica5VgElect.sim

@@ -751,5 +751,6 @@ system sh/exec.sh -n dnode1 -s stop -x SIGINT
 system sh/exec.sh -n dnode2 -s stop -x SIGINT
 system sh/exec.sh -n dnode3 -s stop -x SIGINT
 system sh/exec.sh -n dnode4 -s stop -x SIGINT
+system sh/exec.sh -n dnode5 -s stop -x SIGINT