fixes brotli build issue (#11187)

Co-authored-by: u5surf <u5.horie@gmail.com>

Author: k8s-infra-cherrypick-robot

images/nginx/rootfs/build.sh

@@ -465,10 +465,8 @@ make install
 
 # Get Brotli source and deps
 cd "$BUILD_PATH"
-git clone --depth=100 https://github.com/google/ngx_brotli.git
+git clone --depth=1 https://github.com/google/ngx_brotli.git
 cd ngx_brotli
-# https://github.com/google/ngx_brotli/issues/156
-git reset --hard 63ca02abdcf79c9e788d2eedcc388d2335902e52
 git submodule init
 git submodule update