Qt: libpng warning (exception) about wrong color profile (sRGB)

Problem: libpng warning: iCCP: known incorrect sRGB profile

When debugging Qt applications which load some PNG as icons at startup, it could be annoying to continue with the debugger for each thrown exception.
So, let us fix them.

Invoking $ mogrify *.png in the icon directory will fix them.

How to get mogrify? Install imagemagick.
Either manually or on macOS via homebrew: $ brew install imagemagick

libPNG in version 1.6 has to be at least installed: $ convert -list format | grep PNG