Fix stack trace highlight for PHP

Merged Vitali Tatarintev requested to merge 121714-fix-sentry-stack-trace-highlight-for-php into master

What does this MR do?

Pick a first alternative language for Sentry stack trace highlight, when Rouge can't decide which lexer to choose.

Fixes #121714 (closed)

Screenshots

Screenshot_2019-12-25_10.37.48

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • ~~Label as security and @ mention @gitlab-com/gl-security/appsec~~
  • The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • Security reports checked/validated by a reviewer from the AppSec team