[core/theme] fix mergeing of iconsets

iconsets should only overwrite parameters that are *not* set in the main
theme file.

fixes #666

bumblebee_status/core/theme.py

@@ -53,7 +53,7 @@ def __init__(self, name="default", iconset="auto", raw_data=None):
         self.__data = raw_data if raw_data else self.load(name)
 
         for icons in self.__data.get("icons", []):
-            self.__data = util.algorithm.merge(self.load(icons, "icons"), self.__data)
+            self.__data = util.algorithm.merge(self.__data, self.load(icons, "icons"))
         if iconset != "auto":
             self.__data = util.algorithm.merge(self.load(iconset, "icons"), self.__data)
         for colors in self.__data.get("colors", []):