misc_reactions: move reactions load to on_welcome

edmond/plugins/misc_reactions.py

@@ -32,6 +32,10 @@ class MiscReactionsPlugin(Plugin):
     def __init__(self, bot):
         super().__init__(bot)
         self.priority = -10
+        self.reactions = []
+        self.weights = []
+
+    def on_welcome(self, event):
         self.reactions, self.weights = self.get_reactions()
 
     def get_reactions(self):