org.el (org-fontify-meta-lines-and-blocks-1): Fix fontification bug

* org.el (org-fontify-meta-lines-and-blocks-1): Fix
fontification bug when fontifying a keyword with no associated
value.
Merge branch 'maint'
Revert "org.el (org-fontify-meta-lines-and-blocks-1): Fix fontification bug"

This reverts commit 001b6d1ebdd6e55097e60d4862c9baf98718a002.
Merge branch 'maint'