🐛 Fixed shell script compare operator

Author: mkarlesky

build/plugins/Dockerfile-user

@@ -1,7 +1,7 @@
 
 # Install `reportgenerator` (for `gcov` plugin)
 # Only available in AMD64 containers
-RUN if [ "$TARGETPLATFORM" == "linux/amd64" ]; then set -ex \
+RUN if [ "$TARGETPLATFORM" = "linux/amd64" ]; then set -ex \
   # Install the dotnet tool as global (which means global for the current user vs. a local directory)
   && dotnet tool install --global dotnet-reportgenerator-globaltool \
   # Modify the PATH so the new tool is findable