[FIX] (util): fix extraction of list of keys

They way a list of dictionary keys were extracted apparently was not correct

util/csbusortdirlist.py

@@ -137,8 +137,8 @@ class Basetable():
         os.write("Data stream %s (type %s):\n" %
                 (self.collection, self.datatype))
 
-        years=self.years.keys()
-        channels=self.channels.keys()
+        years=list(self.years.keys())
+        channels=list(self.channels.keys())
 
         years.sort()
         channels.sort()
@@ -317,7 +317,7 @@ def writeoutput(os, tables):
     for k in tables.keys():
         types.append(tables[k].datatype)
 
-    keylist=tables.keys()
+    keylist=list(tables.keys())
     keylist.sort()
     keylist.reverse()