Fix const warning range for loop

[jmackay2]

This fixes the following warning to prevent copying:

error: loop variable 'value' of type 'const std::pair<std::__cxx11::basic_string<char>, int>&' binds to a temporary constructed from type 'const std::pair<const std::__cxx11::basic_string<char>, int>' [-Werror=range-loop-construct] 1873 | for (const std::pair<std::string, INT>& value: COLOR_DICTIONARY) {

[jmackay2]

Fixes #130

[nullket]

Looks good to me but I am still on noetic so I cannot test it.

[SammyRamone]

It removed this error for me. Thanks @jmackay2
I had to do more changes to get it to work, but I think that this was due to the XS camera that I am using. You can see my fork of this fork here https://github.com/SammyRamone/ueye_cam/tree/xs_cam