Fix typo

Change-Id: I7532eeb8845180e2fdf3031e3713480a9fdc1269
Reviewed-on: https://gerrit.libreoffice.org/67709
Tested-by: Jenkins
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>

comphelper/source/misc/threadpool.cxx

@@ -116,7 +116,7 @@ sal_Int32 ThreadPool::getPreferredConcurrency()
         const char *pEnv = getenv("MAX_CONCURRENCY");
         if (pEnv != nullptr)
         {
-            // Override with user/admin preferrence.
+            // Override with user/admin preference.
             nThreads = rtl_str_toInt32(pEnv, 10);
         }