Fix test failures

Replaced sleep in bug676 with wait_for_monitor, removed unsupported
commands from maxinfo_sql.

maxscale-system-test/bug676.cpp

@@ -26,7 +26,7 @@ int main(int argc, char *argv[])
     test.stop_timeout();
 
     test.tprintf("Waiting until the monitor picks a new master");
-    sleep(5);
+    test.maxscales->wait_for_monitor();
 
     test.set_timeout(30);
 

maxscale-system-test/maxinfo_sql.cpp

@@ -14,8 +14,6 @@ int main(int argc, char** argv)
 {
     vector<string> commands(
     {
-        "SET SERVER server1 master",
-        "CLEAR SERVER server1 master",
         "FLUSH LOGS",
         "SHOW VARIABLES",
         "SHOW VARIABLES LIKE '%version%'",