Update comms/gammu to 1.38.2

Changes:
20170328 - 1.38.2
[-] * Improved support for Huawei K3765, E150 and E372.
[-] * Fixed decoding of unicode surrogates at message boundary.
[+] * Environment variable PHONE_ID for external program.
[-] * SMS compatibility with devices following old version of GSM 03.38.
[-] * Unicode is now preferred when handling USSD.
[+] * Improved decoding of MMS indication SMS.

20170105 - 1.38.1
[-] * Fixed sending SMS to numbers starting with 000.
[-] * Fixed parsing of vcalendar files with VALUE=DATE-TIME.
[-] * Fixed compatibility with D-Link dwm-157.
[-] * Updated list of GSM countries and networks.

20161212 - 1.38.0
[-] * MySQL script for SMSD is compatible with strict mode.
[-] * Fixed USSD responses for some AT modems.
[-] * Fixed parsing network status for some modems (eg. Quectel UC15).
[-] * Fixed handling of emojis and other Unicode chars from supplementary plan.
[-] * Fixed compilation with C90 compiler.

(leot)