Improve slave_running check

The current code only consider condition Slave_SQL_Running is yes and
then send slave_running equal 1. We should consider both of condition
are Slave_IO_Running and Slave_SQL_Running to set the value of
slave_running metric.

mysql.py

@@ -398,8 +398,8 @@ def fetch_mysql_slave_stats(conn):
 		if 'delay' in row and row['delay'] != None:
 			status['slave_lag'] = row['delay']
 
-	status['slave_running'] = 1 if slave_row['Slave_SQL_Running'] == 'Yes' else 0
-	status['slave_stopped'] = 1 if slave_row['Slave_SQL_Running'] != 'Yes' else 0
+	status['slave_running'] = 1 if slave_row['Slave_SQL_Running'] == 'Yes' and slave_row['Slave_IO_Running'] == 'Yes' else 0
+	status['slave_stopped'] = 1 if slave_row['Slave_SQL_Running'] != 'Yes' and slave_row['Slave_IO_Running'] != 'Yes' else 0
 	return status
 
 def fetch_mysql_process_states(conn):