NTPServerSync() fails to return the appropriate status upon success for SIM7000G

[cognoquest]

LiLYGOSIMCOM SIM7000G SIM7000G R1529
TinyGSM version: 0.11.7

I am using the AllFunctions.ino example code and implemented the following functions:
TINY_GSM_TEST_GPRS
TINY_GSM_TEST_NTP
TINY_GSM_TEST_TIME

Everything works well during the synchronization, the modem gets updated. The issue that I am having is with the function NTPServerSync returning the value 255 when the synchronization is successful.

For my modem the request network synchronization AT cmd returns more than just the value: 1. It appends to the value: ,"datetime", example of this: 1,"2024/05/23,17:44:42"

Note that I could not find this documented in the SIM7000 Series_AT Command Manual hence no surprise that it is not parsed properly in TinyGSM by the function TinyGsmIsValidNumber.

I recreated/modified the function: TinyGsmIsValidNumber from TinyGsmNTP.tpp with:

`...
if (str.length() >= 2 && str.substring(0, 2).equals("1,")) {return 1;}

if (!(str.charAt(0) == '+' || str.charAt(0) == '-' ||
isDigit(str.charAt(0))))
return false;
...`

By the way great library ... thks