Bump symfony/symfony from 2.8.51 to 2.8.52 in /app

[dependabot[bot]]

Bumps symfony/symfony from 2.8.51 to 2.8.52.

Release notes

Sourced from symfony/symfony's releases.

v2.8.52

Changelog (since https://github.com/symfony/symfony/compare/v2.8.51...v2.8.52)

• security #cve-2019-18888 [HttpFoundation] fix guessing mime-types of files with leading dash (@nicolas-grekas)
• security #cve-2019-18887 [HttpKernel] Use constant time comparison in UriSigner (@stof)

[PR] symfony/symfony#34349 [SECURITY] Security release

Changelog

Sourced from symfony/symfony's changelog.

• 2.8.52 (2019-11-13)

• security #cve-2019-18888 [HttpFoundation] fix guessing mime-types of files with leading dash (nicolas-grekas)

• security #cve-2019-18887 [HttpKernel] Use constant time comparison in UriSigner (stof)

Commits

• 88f3ef6 Merge pull request #34349 from fabpot/release-2.8.52
• 44dbe04 updated VERSION for 2.8.52
• be612fe updated CHANGELOG for 2.8.52
• 2d6bf2e Fix CHANGELOG
• af70ccb security #cve-2019-18888 [HttpFoundation] fix guessing mime-types of files wi...
• d41bd42 security #cve-2019-18887 [HttpKernel] Use constant time comparison in UriSign...
• 2dfc115 [HttpFoundation] fix guessing mime-types of files with leading dash
• 9a50fc5 [HttpKernel] Use constant time comparison in UriSigner
• See full diff in compare view

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