Fix MinGW build failure: conditionally link libssp (#527)

Newer MinGW versions (e.g., GCC 15.2.0) don't provide libssp library,
causing linker errors when building examples. This change makes the
linking conditional by checking if the library exists before attempting
to link it.

Fixes GitHub Actions 'Windows Latest MinGW' build failure:
- cannot find -lssp: No such file or directory

Author: SRombauts

CMakeLists.txt

@@ -459,7 +459,11 @@ if (SQLITECPP_BUILD_EXAMPLES)
 
     target_link_libraries(SQLiteCpp_example1 SQLiteCpp)
     if (MSYS OR MINGW)
-        target_link_libraries(SQLiteCpp_example1 ssp)
+        # Check if libssp exists before linking (newer MinGW versions may not have it)
+        find_library(SSP_LIBRARY ssp)
+        if (SSP_LIBRARY)
+            target_link_libraries(SQLiteCpp_example1 ${SSP_LIBRARY})
+        endif ()
     endif ()
 else (SQLITECPP_BUILD_EXAMPLES)
     message(STATUS "SQLITECPP_BUILD_EXAMPLES OFF")