test: use dynamic port in test-cluster-dgram-reuse
Use of common.PORT in parallel tests is not completely safe (because the same port can be previously assigned to another test running in parallel if that test uses port 0 to get an arbitrary available port).
Remove common.PORT from test-cluster-dgram-reuse.
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
commit message follows commit guidelines
Affected core subsystem(s)
test cluster