chore: remove obsolete replacements from synth.py (#211)
chore: remove obsolete replacements from synth.py (#211)

```
2020-03-05 14:36:59,366 synthtool > No replacements made in **/doc/google/protobuf/doc_timestamp.js for pattern https:\/\/cloud\.google\.com[\s\*]*http:\/\/(.*)[\s\*]*\), maybe replacement is no longer needed?
2020-03-05 14:36:59,378 synthtool > No replacements made in **/doc/google/protobuf/doc_timestamp.js for pattern toISOString\], maybe replacement is no longer needed?
```
googleapis/nodejs-scheduler,googleapis/nodejs-scheduler