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/Fairwaves-SIM.ok b/pysim-testdata/Fairwaves-SIM.ok
index e5fa1af..930dae0 100644
--- a/pysim-testdata/Fairwaves-SIM.ok
+++ b/pysim-testdata/Fairwaves-SIM.ok
@@ -31,7 +31,7 @@
 	ffffff0000 # unused
 
 HPLMNAcT:
-	fff11fffff # MCC: 001 MNC: 001 AcT: UTRAN, E-UTRAN, GSM, GSM COMPACT, cdma2000 HRPD, cdma2000 1xRTT
+	00f110ffff # MCC: 001 MNC: 001 AcT: UTRAN, E-UTRAN, GSM, GSM COMPACT, cdma2000 HRPD, cdma2000 1xRTT
 	ffffff0000 # unused
 	ffffff0000 # unused
 	ffffff0000 # unused