Remove domain init:unix_stream_socket connectto permission.

We do not want to permit connecting to arbitrary unconfined services
left running in the init domain.  I do not know how this was originally
triggered and thus cannot test that it is fixed.  Possible causes:
- another service was left running in init domain, e.g. dumpstate,
- there was a socket entry for the service in the init.rc file
and the service was launched via logwrapper and therefore init did
not know how to label the socket.

The former should be fixed.  The latter can be solved either by
removing use of logwrapper or by specifying the socket context
explicitly in the init.rc file now.

Change-Id: I09ececaaaea2ccafb7637ca08707566c1155a298
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>