Fix build - main_config_name impl is unsafe
Building kconfig-rs currently fails on rustc 1.67.0-nightly (215e3cd21 2022-11-03) with the following error:
error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
--> kconfig-rs/kconfig/src/kconfig.rs:92:9
|
92 | / cpp!([] -> QString as "QString" {
93 | | #if KCONFIG_VERSION >= QT_VERSION_CHECK(5, 93, 0)
94 | | return KConfig::mainConfigName();
95 | | #endif
96 | | })
| |__________^ call to unsafe function
|
This MR marks the cpp
function as unsafe to fix the build