Avoid circular dependency rtp_rtcp <-> paced_sender

webrtc/modules/pacing/pacing.gypi

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'targets': [
     {
       'target_name': 'paced_sender',
       'type': 'static_library',
       'dependencies': [
         '<(webrtc_root)/system_wrappers/system_wrappers.gyp:system_wrappers',
         '<(webrtc_root)/modules/modules.gyp:bitrate_controller',
+        '<(webrtc_root)/modules/modules.gyp:rtp_rtcp',
       ],
       'sources': [
         'include/paced_sender.h',
         'include/packet_router.h',
         'bitrate_prober.cc',
         'bitrate_prober.h',
         'paced_sender.cc',
         'packet_router.cc',
       ],
     },
   ], # targets
 }