armv7 docker compose is broken - no __int128 type
It breaks with:

```#0 120.1 /usr/src/p2pool/src/common.h: In function 'uint64_t p2pool::umul128(uint64_t, uint64_t, uint64_t*)':
#0 120.1 /usr/src/p2pool/src/common.h:127:17: error: expected unqualified-id before '__int128'
#0 120.1   127 |  const unsigned __int128 r = static_cast<unsigned __int128>(a) * static_cast<unsigned __int128>(b);
#0 120.1       |                 ^~~~~~~~
#0 120.2 /usr/src/p2pool/src/common.h:128:8: error: 'r' was not declared in this scope
#0 120.2   128 |  *hi = r >> 64;
#0 120.2       |        ^
```

Log continues further but by groking it it looks like it's all connected to no __int128 type in compiler