* update iOS sdk to 10.3 and add comment

Author: lizhangqu

tools/build-curl4ios.sh

@@ -32,7 +32,8 @@ PLATFORMS=("iPhoneOS" "iPhoneOS" "iPhoneOS" "iPhoneSimulator" "iPhoneSimulator")
 LIB_NAME="curl-7.54.1"
 DEVELOPER=`xcode-select -print-path`
 TOOLCHAIN=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain
-SDK_VERSION=""10.2""
+# If you can't compile with this version, please modify the version to it which on your mac.
+SDK_VERSION=""10.3""
 IPHONEOS_DEPLOYMENT_TARGET="6.0"
 LIB_DEST_DIR="${pwd_path}/../output/ios/curl-universal"
 HEADER_DEST_DIR="include"

tools/build-openssl4ios.sh

@@ -29,7 +29,8 @@ ARCHS=("arm64" "armv7s" "armv7" "i386" "x86_64")
 SDKS=("iphoneos" "iphoneos" "iphoneos" "iphonesimulator" "iphonesimulator")
 PLATFORMS=("iPhoneOS" "iPhoneOS" "iPhoneOS" "iPhoneSimulator" "iPhoneSimulator")
 DEVELOPER=`xcode-select -print-path`
-SDK_VERSION=""10.2""
+# If you can't compile with this version, please modify the version to it which on your mac.
+SDK_VERSION=""10.3""
 LIB_NAME="openssl-1.1.0f"
 LIB_DEST_DIR="${pwd_path}/../output/ios/openssl-universal"
 HEADER_DEST_DIR="include"