Fallback for capsimg path
Created by: sonninnos
Allow placing capsimg library also in the executable path. Aimed at Android+dlopen permission issue:
06-11 15:40:47.611 13410 13429 E linker : library "/storage/emulated/0/RetroArch/system/capsimg.so" ("/storage/emulated/0/RetroArch/system/capsimg.so") needed or dlopened by "/data/data/com.retroarch.ra32/cores/puae_libretro_android.so" is not accessible for the namespace: [ name="classloader-namespace", ld_library_paths="", default_library_paths="/data/app/com.retroarch.ra32-1/lib/arm:/data/app/com.retroarch.ra32-1/base.apk!/lib/armeabi-v7a", permitted_paths="/data:/mnt/expand:/data/data/com.retroarch.ra32" ]