Fix a couple small bugs in markov bot

* .items() call required when loading a markov chain into memory
* `who.nick` instead of `who~ for get_chain call

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

plugins/markov.py

@@ -101,7 +101,7 @@ class Chain:
                         for word, weight in value.items()
                     },
                 )
-                for key, value in obj["chain"]
+                for key, value in obj["chain"].items()
             },
         )
         self.__dirty = False
@@ -192,7 +192,7 @@ class Markov(Plugin):
             self.add(channel, who.nick, line)
             # also, maybe generate a sentence
             chosen = random.random()
-            chain = self.get_chain(channel, who)
+            chain = self.get_chain(channel, who.nick)
             if chosen <= chain.reply_chance:
                 pass