Remove remnants of libsrtp1

webrtc/pc/pc.gyp

 # Copyright (c) 2016 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.
 
 {
   'includes': ['../build/common.gypi'],
   'variables': {
     'rtc_pc_defines': [
-      'SRTP_RELATIVE_PATH',
       'HAVE_SCTP',
       'HAVE_SRTP',
     ],
   },
   'targets': [
     {
       'target_name': 'rtc_pc',
       'type': 'static_library',
       'dependencies': [
         '<(webrtc_root)/base/base.gyp:rtc_base_approved',
@@ skipping 43 matching lines @@
         'mediasession.h',
         'rtcpmuxfilter.cc',
         'rtcpmuxfilter.h',
         'srtpfilter.cc',
         'srtpfilter.h',
         'voicechannel.h',
       ],
     },  # target rtc_pc
   ],  # targets
 }