Remove `const` from return type (#61)
Remove `const` from return type (#61)

Fixes `-Wignored-qualifiers:

```
SimpleIni.h:888:12: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
  888 |     inline const bool SectionExists(
      |            ^~~~~
```
brofield/simpleini,brofield/simpleini