read_elf32 incorrect number conversions

[pavelxdd]

libappimage/src/libappimage/utils/ElfFile.cpp

Line 73 in 3467b20

last_section_end = file64_to_cpu(shdr32.sh_offset) + file64_to_cpu(shdr32.sh_size);

These are 32-bit fields, so file32_to_cpu should be used instead. I don't know if it changes the overall result, but I just noticed this while reading the code.