Fix issue: exception in is_rj45_port in multi ASIC env (sonic-net#2313)

* Fix issue: exception in is_rj45_port in multi ASIC env
Signed-off-by: Stephen Sun <[email protected]>

Author: stephenxs

utilities_common/platform_sfputil_helper.py

@@ -131,10 +131,11 @@ def is_rj45_port(port_name):
         if not platform_porttab_mapping_read:
             platform_sfputil_read_porttab_mappings()
 
-        physical_port = logical_port_name_to_physical_port_list(port_name)[0]
         try:
-            port_type = platform_chassis.get_port_or_cage_type(physical_port)
-        except NotImplementedError as e:
+            physical_port = logical_port_name_to_physical_port_list(port_name)
+            if physical_port:
+                port_type = platform_chassis.get_port_or_cage_type(physical_port[0])
+        except Exception as e:
             port_type = None
 
         return port_type == platform_sfp_base.SFP_PORT_TYPE_BIT_RJ45