Fix case where DSDA not being set in the config caused a crash.

dcc/config.py

@@ -15,7 +15,7 @@ class ConfigBase(object):
             self.doom.joinpath(self.config_name)).read()
 
         self._dsda = self._config.get("dsda")
-        if self.dsda is None:
+        if self._dsda is None:
             raise Exception(
                 "required key 'dsda' not set in config "
                 + f"{self.doom.joinpath(self.config_name)}.")
@@ -37,7 +37,7 @@ class ConfigBase(object):
         propname = "_".join(what)
         val = self._config
         for w in what:
-            val = val[w]
+            val = val.get(w)
             if val is None:
                 val = default
                 break