Fix GCC warning in version.h: use strcmp for string literal comparison

Fixed string literal comparison warning by replacing direct comparison with strcmp() call.
- Added #include <cstring> for strcmp function
- Changed PROJECT_VERSION_CLEAN == "true" to strcmp(PROJECT_VERSION_CLEAN, "true") == 0

Fixes #GCC_WARNING_STRING_COMPARISON

include/version.h.in

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <string>
+#include <cstring>
 
 #define PROJECT_VERSION_FULL "@PROJECT_VERSION_FULL@"
 #define PROJECT_VERSION_TYPE "@PROJECT_VERSION_TYPE@"
@@ -27,7 +28,7 @@ struct VersionInfo {
         commit_short(PROJECT_VERSION_COMMIT),
         commit_full(PROJECT_VERSION_COMMIT_FULL),
         branch(PROJECT_VERSION_BRANCH),
-        is_clean(PROJECT_VERSION_CLEAN == "true"),
+        is_clean(strcmp(PROJECT_VERSION_CLEAN, "true") == 0),
         build_time(PROJECT_VERSION_BUILD_TIME) {}
 };