fixtures: Avoid overly broad exception clause

Author: allanlewis

pytest_flask/fixtures.py

@@ -6,8 +6,9 @@
 import socket
 
 try:
-    from urllib2 import urlopen
+    from urllib2 import URLError, urlopen
 except ImportError:
+    from urllib.error import URLError
     from urllib.request import urlopen
 
 from flask import _request_ctx_stack
@@ -72,7 +73,7 @@ def worker(app, port):
             try:
                 urlopen(self.url())
                 timeout = 0
-            except:
+            except URLError:
                 timeout -= 1
 
     def url(self, url=''):