Fix GCC compile error

Add explicit type conversion

Author: utelle

src/wxsqlite3.cpp

@@ -2684,7 +2684,7 @@ void wxSQLite3Database::Open(const wxString& fileName, const wxMemoryBuffer& key
   wxCharBuffer strFileName = fileName.ToUTF8();
   const char* localFileName = strFileName;
   wxCharBuffer strVfs = vfs.ToUTF8();
-  const char* localVfs = (!vfs.IsEmpty()) ? strVfs : (const char* ) NULL;
+  const char* localVfs = (!vfs.IsEmpty()) ? (const char*) strVfs : (const char*) NULL;
   sqlite3* db;
 
   int rc = sqlite3_open_v2((const char*) localFileName, &db, flags, localVfs);
@@ -2747,7 +2747,7 @@ void wxSQLite3Database::Open(const wxString& fileName, const wxSQLite3Cipher& ci
   wxCharBuffer strFileName = fileName.ToUTF8();
   const char* localFileName = strFileName;
   wxCharBuffer strVfs = vfs.ToUTF8();
-  const char* localVfs = (!vfs.IsEmpty()) ? strVfs : (const char*) NULL;
+  const char* localVfs = (!vfs.IsEmpty()) ? (const char*) strVfs : (const char*) NULL;
   sqlite3* db;
 
   int rc = sqlite3_open_v2((const char*) localFileName, &db, flags, localVfs);