replace old style error catching with 'as' keyword

This is both easier to read and compatible with python3 (not that that
matters)

Signed-off-by: Adrian Tschira <nota@notafile.com>

synapse/app/synctl.py

@@ -38,7 +38,7 @@ def pid_running(pid):
     try:
         os.kill(pid, 0)
         return True
-    except OSError, err:
+    except OSError as err:
         if err.errno == errno.EPERM:
             return True
         return False
@@ -98,7 +98,7 @@ def stop(pidfile, app):
         try:
             os.kill(pid, signal.SIGTERM)
             write("stopped %s" % (app,), colour=GREEN)
-        except OSError, err:
+        except OSError as err:
             if err.errno == errno.ESRCH:
                 write("%s not running" % (app,), colour=YELLOW)
             elif err.errno == errno.EPERM:

synapse/handlers/device.py

@@ -155,7 +155,7 @@ class DeviceHandler(BaseHandler):
 
         try:
             yield self.store.delete_device(user_id, device_id)
-        except errors.StoreError, e:
+        except errors.StoreError as e:
             if e.code == 404:
                 # no match
                 pass
@@ -204,7 +204,7 @@ class DeviceHandler(BaseHandler):
 
         try:
             yield self.store.delete_devices(user_id, device_ids)
-        except errors.StoreError, e:
+        except errors.StoreError as e:
             if e.code == 404:
                 # no match
                 pass
@@ -243,7 +243,7 @@ class DeviceHandler(BaseHandler):
                 new_display_name=content.get("display_name")
             )
             yield self.notify_device_update(user_id, [device_id])
-        except errors.StoreError, e:
+        except errors.StoreError as e:
             if e.code == 404:
                 raise errors.NotFoundError()
             else: