Finally, we managed to publish the game in the store.
From version 2.1.6 source code we have removed all references to network connections (UDP, TCP, Sockets, ...).
We disabled unneeded modules at compilation:
scons p=iphone tools=no bits=32 target=release arch=arm module_openssl_enabled=no module_webp_enabled=no store_kit=no game_center=no tools=no disable_3d=yes disable_advanced_gui=no builtin_libwebp=no builtin_openssl=no module_chibi_enabled=no module_etc1_enabled=no module_pvr_enabled=no module_pbm_enabled=no module_dds_enabled=no module_ik_enabled=no module_cscript_enabled=no builtin_opus=no module_opus_enabled=no module_gridmap_enabled=no
It did not help.
We have removed the unused module from the code. We also removed support for iCloud, the App Store and Game Center.
Then we searched for the word BOLO in assets and discovered it in one of the music files (ogg format). This file was encoded by us from the wav format with oggenc tool. We encoded it again with different parameters.
Apple has approved game in App Store.
We believe that the problem was caused by the contents of the ogg file. Changes to the code probably don't matter, but we're not going to check it out.