Simplify build

cucumber-messages/dotnet/Makefile

@@ -6,12 +6,11 @@ include default.mk
 ifdef ALPINE
 	# The protoc bundled in the grpc.tools nuget package doesn't work on Alpine,
 	# so we overwrite it with the one bundled inside the Docker image.
-	# In order to prevent nuget from overwriting it again, we first build
-	# once, allowing the build to fail, then doing the copy.
-	-dotnet restore
+	# In order to prevent nuget from overwriting it again, we first 
+	# doewnload the nuget packages, then doing the copy.
+	dotnet restore
 	mkdir -p /root/.nuget/packages/grpc.tools/1.20.1/tools/linux_x64
 	cp /usr/bin/protoc /root/.nuget/packages/grpc.tools/1.20.1/tools/linux_x64/protoc
-	-dotnet build -bl -c Release
 endif
 	touch $@