HRIR losses due to rounding

[David-Rodriguez-Lobaco]

In HRTF.cpp, void CHRTF::AddHRIR (float azimuth, float elevation, THRIRStruct && newHRIR), line 66, there is a problem when rounding Azimuth and Elevation.

Using some databases, such as "H3_48K_24bit_256tap_FIR_SOFA.sofa", whose azimuth has some decimal data, cause an error using emplace.

For example:

the data 75 and 91 have same elevation(-81) but different azimuth(12.8 and 13.3). When rounding, this two azimuth will be the same (13). So, using emplace the first time will place the data in { 13, -81} , but the second time it will see there is already data in that position and descard it.