[irods/irods#4622] set ReplicaNum to "null" in rulemsiDataObjPhymv.r

Supplying a replica number in the call to msiDataObjPhymv made the test
fail.

First point of reference: since resolution of irods/irods#4622, not more than
one replica exists per storage resource anyway, so no specification
of replica number is needed if the source resource for phymv is given.
Giving "null" in place of a concrete integer was the solution.

Second point of reference:  2f1b1dbe7f621554f4f7fbd12a77ba144f312e50 in irods/irods
now enforces that iphymv -S [source resource] and -n [replnum] are incompatible
parameters.

Author: d-w-moore

python_rules/rulemsiDataObjPhymv.r

@@ -8,5 +8,5 @@ def main(rule_args, callback, rei):
 
     callback.writeLine('stdout', 'Replica number ' + replica_number + 'of file ' + source_file + ' is moved from resource ' + source_resource + ' to resource ' + dest_resource)
 
-INPUT *SourceFile="/tempZone/home/rods/forphymv/phymvfile", *DestResource="testallrulesResc", *SourceResource="demoResc", *ReplicaNumber="0"
+INPUT *SourceFile="/tempZone/home/rods/forphymv/phymvfile", *DestResource="testallrulesResc", *SourceResource="demoResc", *ReplicaNumber="null"
 OUTPUT ruleExecOut