Compilation error when trying to use FONA with an ESP32 TTGO T Call module

[papyreparetout]

• Arduino board: ESP32 TTGO T Call

• Arduino IDE version (found in Arduino -> About Arduino menu): 1.8.10

• List the steps to reproduce the problem below (if possible attach a sketch or
  copy the sketch code in too): LIST REPRO STEPS BELOW

When trying to use the library I got a compilation error due to non return statement in function
boolean Adafruit_FONA::readRTC
and there was no return statement in that function
to solve the problem I add : return true; at the end of the function (I was not using it so I guess it was not a problem for me)
After doing that the compilation was OK and the program executed as I expected.