Update SDL2_Pango to version 2.1.5 / rev 1 via SR 1059422
https://build.opensuse.org/request/show/1059422
by user badshah400 + dimstar_suse
This is a library for graphically rendering internationalized and tagged text in SDL2. It will be needed by several apps (e.g. tuxpaint) when we switch to building them against SDL2 instead of SDL(1).