Redundent interface build

[yswhynot]

I was running into compilation error when doing catkin build with Ubuntu 14.04 and cmake 3.5.1.
The error shows

CMake Error at $CATKIN_WS/src/rtmros_common/rtmbuild/cmake/rtmbuild.cmake:265 (add_custom_target):
  add_custom_target cannot create target
  "RTMBUILD_openrtm_ros_bridge_MyService_genbridge" because another target
  with the same name already exists.  The existing target is a custom target
  created in source directory
  "$CATKIN_WS/src/rtmros_common/openrtm_ros_bridge".

I figured out it should be that there are two services from the same interface called MyService thus the rtmbuild tries to build it twice. Then it fails in the second time.
I think this is a fix for this problem.

[k-okada]

@yswhynot Hi, I think the issue is similar to jsk-ros-pkg/jsk_common#1586, but I think this hould not happens if you uses catkin build. So, can you provide full output of your 'catkin build'

[yswhynot]

Hi, I've provided with the full log here: #1047
I think it's different jsk-ros-pkg/jsk_common#1586 since it's from the same package. I guess it might be a better solution if they build in the order that the parent interface is built first.