fix: read source.json with utf-8

plugins/plugin_manager.py

@@ -220,7 +220,7 @@ class PluginManager:
         
         if not match:
             try:
-                with open("./plugins/source.json","r") as f:
+                with open("./plugins/source.json","r", encoding="utf-8") as f:
                     source = json.load(f)
                 if repo in source["repo"]:
                     repo = source["repo"][repo]["url"]
@@ -238,7 +238,7 @@ class PluginManager:
             if os.path.exists(os.path.join(dirname,"requirements.txt")):
                 logger.info("detect requirements.txt，installing...")
             pkgmgr.install_requirements(os.path.join(dirname,"requirements.txt"))
-            return True, "安装插件成功，请使用#scanp命令扫描插件或重启程序"
+            return True, "安装插件成功，请使用 #scanp 命令扫描插件或重启程序"
         except Exception as e:
             logger.error("Failed to install plugin, {}".format(e))
             return False, "安装插件失败，"+str(e)