modem_atcmd: raise ProtocolError instead of ReaderError on CME ERROR

Also accept ProtocolError in addition to SwMatchError in filesystem.py
when probing for applications

Change-Id: I82b50408328f8eaaee5c9e311c4620d20f930642
diff --git a/pySim/filesystem.py b/pySim/filesystem.py
index ce1882b..b5d0ccd 100644
--- a/pySim/filesystem.py
+++ b/pySim/filesystem.py
@@ -1352,7 +1352,7 @@
                 if sw == "9000":
                     print(" %s: %s" % (f.name, f.aid))
                     apps_taken.append(f)
-            except SwMatchError:
+            except (SwMatchError, ProtocolError):
                 pass
         return apps_taken