fix parl version import error (#1399)

paddleslim/common/rl_controller/__init__.py

@@ -16,7 +16,6 @@ import logging
 from ..log_helper import get_logger
 _logger = get_logger(__name__, level=logging.INFO)
 try:
-    import parl
     from .ddpg import *
 except ImportError as e:
     pass

paddleslim/common/rl_controller/ddpg/__init__.py

@@ -12,4 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from .ddpg_controller import *
+import logging
+
+try:
+    from .ddpg_controller import *
+except Exception as e:
+    logging.warning(e)