telit: fix supported and current bands query with GE910

GE910 is a 2g only modem and when queried for bands it returns
only a 2g set of bands:

--> 'AT#BND=?<CR>'
<-- '<CR><LF>#BND: (0-3)<CR><LF><CR><LF>OK<CR><LF>'

Current regex fails, since it considers the 3g bands block mandatory.

A similar problem happens for current bands.

This patch modifies the regular expressions for properly
supporting GE910 and updates tests.

plugins/telit/tests/test-mm-modem-helpers-telit.c

@@ -160,6 +160,10 @@ typedef struct {
 } BNDResponseTest;
 
 static BNDResponseTest supported_band_mapping_tests [] = {
+    { "#BND: (0-3)", TRUE, FALSE, FALSE, 4, { MM_MODEM_BAND_EGSM,
+                                              MM_MODEM_BAND_DCS,
+                                              MM_MODEM_BAND_PCS,
+                                              MM_MODEM_BAND_G850} },
     { "#BND: (0-3),(0,2,5,6)", TRUE, TRUE, FALSE, 7, { MM_MODEM_BAND_EGSM,
                                                       MM_MODEM_BAND_DCS,
                                                       MM_MODEM_BAND_PCS,
@@ -242,6 +246,10 @@ test_parse_supported_bands_response (void) {
 
 
 static BNDResponseTest current_band_mapping_tests [] = {
+    { "#BND: 0", TRUE, FALSE, FALSE, 2, { MM_MODEM_BAND_EGSM,
+                                          MM_MODEM_BAND_DCS
+                                        }
+    },
     { "#BND: 0,5", TRUE, TRUE, FALSE, 3, { MM_MODEM_BAND_EGSM,
                                            MM_MODEM_BAND_DCS,
                                            MM_MODEM_BAND_U900