www/rubygem-passenger: Update to 6.0.19

• Update WWW
• Use ECHO_CMD instead of ECHO
• Clean up Makefile
  • Remove unnecessary USES=shebangfix
  • Remove CPE_PRODUCT
  • Remove RAKE_BIN
  • Remove no-op REINPLACE_CMD
• Take maintainership

Changes: https://github.com/phusion/passenger/releases