Breaking: #66906 - Automatic PNG to GIF conversion removed 

See forge#66906

Description 

The configuration setting $TYPO3_CONF_VARS[GFX][png_to_gif] has been removed.

Impact 

If the option is set in an installation, then PNG images used in the TYPO3 Frontend will now be kept as PNG, instead of converting them to GIF files.

Affected Installations 

Installations having the option $TYPO3_CONF_VARS[GFX][png_to_gif] activated.