Fix reference for left version of StVO 214 (#383)

Documentation bug probably due to 2017 renumbering of signs

Author: pmai

osi_trafficsign.proto

@@ -1333,7 +1333,7 @@ message TrafficSign
                 // </tr>
                 // </table>
                 //
-                // Left: \c #TYPE_PRESCRIBED_LEFT_TURN_AND_RIGHT_TURN
+                // Left: \c #TYPE_PRESCRIBED_LEFT_TURN_AND_STRAIGHT
                 //
                 // As symbolic road marking \c
                 // RoadMarking::Classification::TYPE_SYMBOLIC_TRAFFIC_SIGN