[3399] Parameters are now printed during exception

src/bin/dhcp4/ctrl_dhcp4_srv.cc

@@ -97,7 +97,8 @@ ControlledDhcpv4Srv::processCommand(const string& command,
         return (answer);
     } catch (const Exception& ex) {
         return (isc::config::createAnswer(1, "Error while processing command '"
-                                          + command + "':" + ex.what()));
+                                          + command + "':" + ex.what() +
+                                          ", params: '" + args->str() + "'"));
     }
 }