By changing the declaration of `capacity` to unsigned integer
in createBloomFilter() we fixed the following warning:

```
../../src/cashlib/cashlib.cpp: In function ‘int createBloomFilter(const unsigned char*, unsigned int, unsigned int, double, int, int, int, int, unsigned char*)’:
../../src/cashlib/cashlib.cpp:1449:26: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]
 1449 |     int maxx = (capacity > len) ? capacity : len;
      |                 ~~~~~~~~~^~~~~
```