Merge pull request #1797 from KhronosGroup/clone-protocol

Always use https protocol when cloning external test deps.
diff --git a/README.md b/README.md
index 98a38df..7d6520c 100644
--- a/README.md
+++ b/README.md
@@ -444,9 +444,6 @@
 
 ```
 ./checkout_glslang_spirv_tools.sh # Checks out glslang and SPIRV-Tools at a fixed revision which matches the reference output.
-                                  # NOTE: Some users have reported problems cloning from git:// paths. To use https:// instead pass in
-                                  # $ PROTOCOL=https ./checkout_glslang_spirv_tools.sh
-                                  # instead.
 ./build_glslang_spirv_tools.sh    # Builds glslang and SPIRV-Tools.
 ./test_shaders.sh                 # Runs over all changes and makes sure that there are no deltas compared to reference files.
 ```
diff --git a/checkout_glslang_spirv_tools.sh b/checkout_glslang_spirv_tools.sh
index 400f7cb..24a74fb 100755
--- a/checkout_glslang_spirv_tools.sh
+++ b/checkout_glslang_spirv_tools.sh
@@ -5,12 +5,7 @@
 GLSLANG_REV=3de5cfe50edecd001e6d703555284d9b10b3dd57
 SPIRV_TOOLS_REV=f3ccb633dfd7c5de1f9f0a2d2e9d7a25f2478206
 SPIRV_HEADERS_REV=f027d53ded7e230e008d37c8b47ede7cd308e19d
-
-if [ -z $PROTOCOL ]; then
-	PROTOCOL=git
-fi
-
-echo "Using protocol \"$PROTOCOL\" for checking out repositories. If this is problematic, try PROTOCOL=https $0."
+PROTOCOL=https
 
 if [ -d external/glslang ]; then
 	echo "Updating glslang to revision $GLSLANG_REV."