PgDB: fix connect() return and improve logging

PgDB.py

@@ -25,14 +25,23 @@ class PgDB(object):
 		self.pwd  = pwd
 		self.db   = db
 
-	def connect(self):
-		if self.con == 0:
-			try:
-				con = psycopg2.connect("dbname='%s' user='%s' host='%s' password='%s'" % (self.db,self.user,self.host,self.pwd))
-				self.con = con
-			except Exception:
-				logging.fatal('An error occured during Postgresql database connection.', exc_info=1)
-				sys.exit(1)
+    def connect(self):
+        if self.con == 0:
+            try:
+                con = psycopg2.connect(
+                    dbname=self.db,
+                    user=self.user,
+                    host=self.host,
+                    password=self.pwd
+                )
+                self.con = con
+            except Exception:
+                logging.fatal(
+                    'An error occured during Postgresql database connection (%s@%s, database=%s).',
+                    self.user, self.host, self.db, exc_info=1
+                )
+                sys.exit(1)
+        return True
 
 	def close(self):
 		if self.con: