modulecmd: bugfix in loading multiple modules in same call of module

If more than one module is passed to the module function, loading
failed if one of the modules is already loaded as dependency.

Pmodules/modulecmd.bash.in

@@ -892,6 +892,8 @@ subcommand_load() {
 		fi
 		test -r "${deps_file}" && load_dependencies "$_"
 
+		[[ ":${LOADEDMODULES}:" == *:${m}:* ]] && continue
+
 		# load module
 		modulecmd="${interp[${current_modulefile}]}"
 		local output=''