Bump proj4php/proj4php from 2.0.17 to 2.0.18

Bumps [proj4php/proj4php](https://github.com/proj4php/proj4php) from 2.0.17 to 2.0.18.
- [Release notes](https://github.com/proj4php/proj4php/releases)
- [Commits](proj4php/proj4php@2.0.17...v2.0.18)

---
updated-dependencies:
- dependency-name: proj4php/proj4php
  dependency-version: 2.0.18
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]