org.el (org-scan-tags): Fix bug when building the scanner regexp.

* org.el (org-scan-tags): Fix bug when building the scanner regexp.

Thanks to Mike McLean, who first reported this issue and provided a
reproducible recipe.  Thanks to Laurynas Biveinis and Loris Bennett
who provided complementary feedback on this.

lisp/org.el

@@ -12828,10 +12828,7 @@ headlines matching this string."
 		       org-outline-regexp)
 		     " *\\(\\<\\("
 		     (mapconcat 'regexp-quote org-todo-keywords-1 "\\|")
-		     (org-re
-		      (if todo-only
-			  "\\>\\)\\)[ \t]+\\(.*?\\)\\(:[[:alnum:]_@#%:]+:\\)?[ \t]*$"
-			"\\>\\)\\)? *\\([^ ].*?\\)\\(:[[:alnum:]_@#%:]+:\\)?[ \t]*$"))))
+		     (org-re "\\)\\>\\)? *\\(.*?\\)\\(:[[:alnum:]_@#%:]+:\\)?[ \t]*$")))
 	 (props (list 'face 'default
 		      'done-face 'org-agenda-done
 		      'undone-face 'default