Revert "Fix one more string/bytes issue in lldb-server tests"

It looks like I was too hasty to submit the previous patch. It does fix
some tests on python3, but it also breaks one tests with python2.

This happens because the gdb-remote protocol can sometimes (but not very
often) contain binary data, and attempting to parse this as utf8
characters fails.

This reverts commit r353944.

llvm-svn: 353945

lldb/packages/Python/lldbsuite/test/tools/lldb-server/socket_packet_pump.py

@@ -174,7 +174,7 @@ class SocketPacketPump(object):
             can_read, _, _ = select.select([self._socket], [], [], 0)
             if can_read and self._socket in can_read:
                 try:
-                    new_bytes = self._socket.recv(4096).decode("utf-8")
+                    new_bytes = self._socket.recv(4096)
                     if self._logger and new_bytes and len(new_bytes) > 0:
                         self._logger.debug(
                             "pump received bytes: {}".format(new_bytes))