Flip (back) `pikerd` to use TCP by default

It'll break all non-linux OS-platforms atm and bc it should only be set
to a "non-std transport" through the config anyways.

Yeah yeah, we're slowly appealing to the frickin masses..

piker/cli/__init__.py

@@ -183,8 +183,8 @@ def pikerd(
                 registry_addrs=regaddrs,
                 loglevel=loglevel,
                 debug_mode=pdb,
-                enable_transports=['uds'],
-                # enable_transports=['tcp'],
+                # enable_transports=['uds'],
+                enable_transports=['tcp'],
             ) as service_mngr,
         ):
             assert service_mngr