minor #2116 'empty(...)' usage (grachevko, javiereguiluz)
minor #2116 'empty(...)' usage (grachevko, javiereguiluz)

This PR was merged into the 2.0.x-dev branch.

Discussion
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'empty(...)' usage

https://github.com/kalessil/phpinspectionsea/blob/master/docs/types-compatibility.md#empty-usage

Commits
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6aed2f30 Restore some occurrences of empty()
31d526e3 Remove null comparison
b5db33c6 'empty(...)' usage

yceruto/EasyAdminBundle,OskarStark/EasyAdminBundle,yceruto/EasyAdminBundle,OskarStark/EasyAdminBundle,javiereguiluz/EasyAdminBundle,javiereguiluz/EasyAdminBundle,yceruto/EasyAdminBundle,OskarStark/EasyAdminBundle