mattermost change the version git checkout

Signed-off-by: webbuilder_pel7ppc64lebuilder0 <webbuilder@powerel.org>

SPECS/mattermost.spec

@@ -39,7 +39,7 @@ git clone https://github.com/mattermost/mattermost-webapp/
 export GOPATH=`pwd`
 export GO111MODULE=on
 pushd src/github.com/mattermost/mattermost-server/
-git checkout tags/v%{version}
+git checkout v%{version}
 git submodule update --init --recursive
 go get -d ./...
 %ifarch ppc64 ppc64le
@@ -48,7 +48,7 @@ sed 's/amd64/%{_arch}/g' -i build/release.mk
 make build-linux
 popd
 pushd src/github.com/mattermost/mattermost-webapp/
-git checkout tags/v%{version}
+git checkout v%{version}
 npm install --save
 # we need to patch optipng from npm
 git clone https://github.com/imagemin/optipng-bin node_modules/optipng-bin/