Remove x86 from build_ios_libs.

iOS 12.0 is the new iOS deployment target and iOS 10 is the maximum
deployment target for 32-bit targets.

Bug: webrtc:12928
Change-Id: I60f300c991cc67f826b2bff56415ed8e20cee77f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/224845
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34415}
diff --git a/tools_webrtc/ios/build_ios_libs.py b/tools_webrtc/ios/build_ios_libs.py
index 58c95e4..5aa40d6 100755
--- a/tools_webrtc/ios/build_ios_libs.py
+++ b/tools_webrtc/ios/build_ios_libs.py
@@ -30,7 +30,7 @@
 SDK_OUTPUT_DIR = os.path.join(SRC_DIR, 'out_ios_libs')
 SDK_FRAMEWORK_NAME = 'WebRTC.framework'
 
-DEFAULT_ARCHS = ENABLED_ARCHS = ['arm64', 'x64', 'x86']
+DEFAULT_ARCHS = ENABLED_ARCHS = ['arm64', 'x64']
 IOS_DEPLOYMENT_TARGET = '12.0'
 LIBVPX_BUILD_VP9 = False