IF NOT EXISTS is not present in some sqlite

versions

src/common/check_paths.py

@@ -37,7 +37,21 @@ from pysqlite2 import dbapi2 as sqlite # DO NOT MOVE ABOVE OF import gajim
 
 def assert_um_exists():
 	''' create table unread_messages if there is no such table '''
-	pass
+	con = sqlite.connect(logger.LOG_DB_PATH) 
+	cur = con.cursor()
+	cur.executescript(
+			'''
+			CREATE TABLE unread_messages (
+				message_id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE
+			);
+			'''
+			)
+	try:
+		con.commit()
+		gajim.logger.init_vars()
+	except sqlite.OperationalError, e:
+		pass
+	con.close()
 	
 def create_log_db():
 	print _('creating logs database')