fix: optimization: PVS-Studio warning V825

The 'current.reset(lang.release())' expression is equivalent to 'current = std::move(lang)'.
Changed 'current.reset(lang.release())' to 'current = std::move(lang)' to improve code clarity and performance.

Reported by: PVS-Studio

Signed-off-by: Vyacheslav Ivanov <islavaivanov76@gmail.com>

src/frontend/locale.cpp

@@ -146,7 +146,7 @@ void langs::load(const fs::path& resdir,
     if (locale != fallback) {
         load(resdir, locale, packs, *lang.get());
     }
-    current.reset(lang.release());
+    current = std::move(lang);
 }
 
 void langs::setup(const fs::path& resdir,