With a non-zero send delay, the communication over the ttyACM port of
the modem is not very stable when USB auto-suspend is enabled for the
modem. The send delay is not necessary and thus removed by this patch.
Ori Inbar <ori.inbar@altair-semi.com> reported the issue and suggested
this fix.
This patch fixes a potential crash when
MMIfaceModem::load_current_bands_ready() dereferences a NULL GError
pointer, which happens when the altair-lte plugin fails to load the
current bands but does not propagate the error. It also fixes a similar
issue with the plugin fails to load the supported bands, even though
MMIfaceModem::load_supported_bands_ready() checks for a NULL GError
pointer.
