Fix statsd client on urls that aren't ascii encodable

Fixes https://sentry.galaxyproject.org/share/issue/e2c535d2d4904d438a0a1524c991bba4/:
```
UnicodeEncodeError: 'ascii' codec can't encode characters in position 14-16: ordinal not in range(128)
  File "galaxy/web/framework/middleware/error.py", line 167, in __call__
    app_iter = self.application(environ, sr_checker)
  File "galaxy/web/framework/middleware/statsd.py", line 34, in __call__
    self.galaxy_stasd_client.timing(page, dt)
  File "galaxy/web/statsd_client.py", line 35, in timing
    self.statsd_client.timing(infix + path, time)
  File "statsd/client/base.py", line 33, in timing
    self._send_stat(stat, '%0.6f|ms' % delta, rate)
  File "statsd/client/base.py", line 61, in _send_stat
    self._after(self._prepare(stat, value, rate))
  File "statsd/client/base.py", line 76, in _after
    self._send(data)
  File "statsd/client/udp.py", line 42, in _send
    self._sock.sendto(data.encode('ascii'), self._addr)
```

lib/galaxy/web/framework/middleware/statsd.py

@@ -28,8 +28,13 @@ def __call__(self, environ, start_response):
         start_time = time.time()
         req = self.application(environ, start_response)
         dt = int((time.time() - start_time) * 1000)
-        page = environ.get("controller_action_key", None) or environ.get("PATH_INFO", "NOPATH").strip("/").replace(
-            "/", "."
+        page = (
+            environ.get("controller_action_key", None)
+            or environ.get("PATH_INFO", "NOPATH")
+            .strip("/")
+            .replace("/", ".")
+            .encode("ascii", errors="replace")
+            .decode()
         )
         self.galaxy_stasd_client.timing(page, dt)
         try: