plugins cmd space in filename

rel/files/emqttd.cmd

@@ -76,7 +76,7 @@ cd /d !dest_path!..\plugins
 set current_path=%cd%
 set plugins=
 for /d %%P in (*) do (
-set "plugins=!plugins!!current_path!\%%P\ebin "
+set "plugins=!plugins!"!current_path!\%%P\ebin" "
 )
 cd /d %node_root%
 

rel/files/start_erl.cmd

@@ -40,7 +40,7 @@ cd /d !dest_path!..\plugins
 set current_path=%cd%
 set plugins=
 for /d %%P in (*) do (
-set "plugins=!plugins!!current_path!\%%P\ebin "
+set "plugins=!plugins!"!current_path!\%%P\ebin" "
 )
 cd /d %node_root%
 @%erl_exe% %erl_args% -boot %boot_file% -config %app_config% -args_file %vm_args% -pa %plugins%