Log Message:
erlang-stringprep: Update to 1.O.24

upstream changes:
-----------------
Version 1.0.24
  * Updating p1_utils to version 1.0.21.

Version 1.0.23
  * Exclude old OTP releases from Travis
  * Fix hex to support compiling ejabberd with rebar3

Version 1.0.22
  * Updating p1_utils to version 1.0.20.

Version 1.0.21
  * Fix compilation with Erlang/OTP 23.0, and Travis

Version 1.0.20
  * Updating p1_utils to version 1.0.19.

Version 1.0.19
  * Updating p1_utils to version 1.0.18.
  * Update copyright year

Version 1.0.18
  * Updating p1_utils to version 1.0.17.

Version 1.0.17
  * Updating p1_utils to version 1.0.16.

Version 1.0.16
  * Updating p1_utils to version 1.0.15.

Version 1.0.15
  * Updating p1_utils to version 1.0.14.
  * Add contribution guide
  * Fix license discrepancies

Version 1.0.14
  * Updating p1_utils to version 1.0.13.

Version 1.0.13
  * Updating p1_utils to version 6ff85e8.