[dist] Add :production group to find_requires script

otherwise frontend will not start because of missing dependencies.

dist/find-requires.sh

@@ -17,7 +17,7 @@ ruby.ruby2.4 -rbundler -e 'exit' || echo "___ERROR_BUNDLER_NOT_INSTALLED___"
 
 mode="resolve"
 if [ "$limit" == "production" ]; then
-  mode="specs_for([:default, :assets])"
+  mode="specs_for([:default, :production, :assets])"
 fi
 
 ruby.ruby2.4 -rbundler -e 'Bundler.definition.'"$mode"'.any? { |s| puts "rubygem('$prefix':#{s.name}) = #{s.version}" }' | while read i; do echo -n $i", "; done