[Python 3 compability] decode function used in 'needsQuoting' function

is not available on Python 3.

web/pgadmin/utils/driver/psycopg2/__init__.py

@@ -797,8 +797,12 @@ class Driver(BaseDriver):
     @staticmethod
     def needsQuoting(key, forTypes):
 
+        # Python 3 does not require the decoding of value
+        if hasattr(str, 'decode'):
             value = key.decode()
-            valNoArray = value.decode()
+        else:
+            value = key
+        valNoArray = value
 
         # check if the string is number or not
         if (isinstance(value, int)):