Fix windows build failure

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

sql/sql_manager.cc

@@ -30,7 +30,7 @@
   Values for manager_thread_in_use: 0 means "not started". 1 means "started
   and active". 2 means "stopped".
 */
-static bool volatile manager_thread_in_use = 0;
+static int volatile manager_thread_in_use = 0;
 static bool abort_manager = false;
 
 pthread_t manager_thread;