sysmoUSIM-SJS1: enable USIM mode before testing

sysmoUSIM-SJS1 features enableing/disableing its USIM application to
switch beween classic SIM and USIM mode. If the usim mode gets disabled
by excidant the testsuite would fail. Lets make sure that USIM mode is
always enabled before the testsuite is executed.

tests/sjs1/prepare

@@ -3,6 +3,7 @@
 . ./test-data
 
 echo "================ PREPARING TEST CARD ================"
+$TOOL -a $ADMPIN -u
 $TOOL -a $ADMPIN -I $ICCID
 $TOOL -a $ADMPIN -J $IMSI
 echo "================ TEST CARD PREPARED ================="