Bump iOS min supported version to 10.0

Bug: webrtc:10329
Change-Id: Ica1f858624e952317bc6802b5e13c6f973ceb5ed
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/124830
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27017}
diff --git a/.gn b/.gn
index 9110455..5c9f362 100644
--- a/.gn
+++ b/.gn
@@ -63,8 +63,7 @@
 
   mac_sdk_min = "10.12"
 
-  # http://bugs.webrtc.org/8570
-  ios_deployment_target = "9.0"
+  ios_deployment_target = "10.0"
 
   # The SDK API level, in contrast, is set by build/android/AndroidManifest.xml.
   android32_ndk_api_level = 16