Softethervpn doesn't compile libmayaqua.so: UNDEFINED REFERENCE to ENGINE_by_id - FIXED by neheb?

Can't compile SoftEtherVPN-5.02.5180 server

Maintainer: @fededim
Environment: ipq806x. Archer C2600 21.02-rc3

Description:

[ 98%] Linking C executable ../../vpnserver
/home/gabriele/openwrt/21/staging_dir/toolchain-arm_cortex-a15+neon-vfpv4_gcc-8.4.0_musl_eabi/lib/gcc/arm-openwrt-linux-muslgnueabi/8.4.0/../../../../arm-openwrt-linux-muslgnueabi/bin/ld: ../../libmayaqua.so: undefined reference to ENGINE_load_private_key' /home/gabriele/openwrt/21/staging_dir/toolchain-arm_cortex-a15+neon-vfpv4_gcc-8.4.0_musl_eabi/lib/gcc/arm-openwrt-linux-muslgnueabi/8.4.0/../../../../arm-openwrt-linux-muslgnueabi/bin/ld: ../../libmayaqua.so: undefined reference to ENGINE_by_id'
/home/gabriele/openwrt/21/staging_dir/toolchain-arm_cortex-a15+neon-vfpv4_gcc-8.4.0_musl_eabi/lib/gcc/arm-openwrt-linux-muslgnueabi/8.4.0/../../../../arm-openwrt-linux-muslgnueabi/bin/ld: ../../libmayaqua.so: undefined reference to `ENGINE_init'
collect2: error: ld returned 1 exit status
make[7]: *** [src/vpnserver/CMakeFiles/vpnserver.dir/build.make:106: vpnserver] Error 1
make[7]: Leaving directory '/home/gabriele/openwrt/21/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/SoftEtherVPN-5.02.5180'
make[6]: *** [CMakeFiles/Makefile2:460: src/vpnserver/CMakeFiles/vpnserver.dir/all] Error 2
make[6]: Leaving directory '/home/gabriele/openwrt/21/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/SoftEtherVPN-5.02.5180'
make[5]: *** [CMakeFiles/Makefile2:467: src/vpnserver/CMakeFiles/vpnserver.dir/rule] Error 2
make[5]: Leaving directory '/home/gabriele/openwrt/21/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/SoftEtherVPN-5.02.5180'
make[4]: *** [Makefile:270: vpnserver] Error 2
make[4]: Leaving directory '/home/gabriele/openwrt/21/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/SoftEtherVPN-5.02.5180'
make[3]: *** [Makefile:176: /home/gabriele/openwrt/21/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/SoftEtherVPN-5.02.5180/.built] Error 2
make[3]: Leaving directory '/home/gabriele/openwrt/21/feeds/packages/net/softethervpn5'
time: package/feeds/packages/softethervpn5/compile#0.61#0.43#0.96
ERROR: package/feeds/packages/softethervpn5 failed to build.
make[2]: *** [package/Makefile:114: package/feeds/packages/softethervpn5/compile] Error 1
make[2]: Leaving directory '/home/gabriele/openwrt/21'
make[1]: *** [package/Makefile:108: /home/gabriele/openwrt/21/staging_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/stamp/.package_compile] Error 2
make[1]: Leaving directory '/home/gabriele/openwrt/21'
make: *** [/home/gabriele/openwrt/21/include/toplevel.mk:230: world] Error 2

Start with the softethervpn5 package build and the linker output for libmayaqua.so, then verify whether the issue is still reproducible on the stated OpenWrt environment. Check the issue thread for the reported fix by neheb; done means the package compiles without the ENGINE_by_id, ENGINE_init, and ENGINE_load_private_key undefined references.