Treat MCC and MNC as strings, not integers

A MNC of 02 and 002 are *not* equal.  The former is a two-digit MNC
and the latter is a three-digit MNC.  Hence, we shouldn't treat
MNCs as integer values as we have no clue how many leading zeroes
(if any) the user entered.

Change-Id: I9d1d07a64888c76703c3e430bbdd822080c05819
Closes: OS#4523
diff --git a/pysim-testdata/fakemagicsim.ok b/pysim-testdata/fakemagicsim.ok
index 0168b13..7ac9e2a 100644
--- a/pysim-testdata/fakemagicsim.ok
+++ b/pysim-testdata/fakemagicsim.ok
@@ -10,7 +10,7 @@
 SPN: Magic
 Display HPLMN: True
 Display OPLMN: False
-PLMNsel: fff11fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
+PLMNsel: 00f110ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
 PLMNwAcT: Can't read file -- SW match failed! Expected 9000 and got 9404.
 OPLMNwAcT: Can't read file -- SW match failed! Expected 9000 and got 9404.
 HPLMNAcT: Can't read file -- SW match failed! Expected 9000 and got 9404.