Fix: Priority queries for headings with certain to-do keywords

When query preambles are enabled, headings with to-do keywords
containing non-alphabetic characters, like "TO-READ", would fail to
match queries like (priority "A").

Released as 0.2.3.

README.org

@@ -441,6 +441,11 @@ Expands into a call to ~org-ql-select~ with the same arguments.  For convenience
 
 /Note:/ Breaking changes may be made before version 1.0, but in the event of major changes, attempts at backward compatibility will be made with obsolescence declarations, translation of arguments, etc.  Users who need stability guarantees before 1.0 may choose to use tagged stable releases.
 
+** 0.2.3
+
+*Fixed*
++  Priority queries could fail to match headings whose to-do keywords had non-alphabetic characters, like =TO-READ=.
+
 ** 0.2.2
 
 *Fixed*

org-ql.el

@@ -2,7 +2,7 @@
 
 ;; Author: Adam Porter <adam@alphapapa.net>
 ;; Url: https://github.com/alphapapa/org-ql
-;; Version: 0.2.2
+;; Version: 0.2.3
 ;; Package-Requires: ((emacs "26.1") (dash "2.13") (org "9.0") (s "1.12.0") (ts "0.2"))
 ;; Keywords: hypermedia, outlines, Org, agenda
 
@@ -460,7 +460,7 @@ replace the clause with a preamble."
                                 (`(priority ,letter)
                                  ;; Specific priority without comparator.
                                  (setq org-ql-preamble (rx-to-string `(seq bol (1+ "*") (1+ blank)
-                                                                           (optional (1+ upper) (1+ blank))
+                                                                           (0+ nonl) (1+ blank)
                                                                            "[#" ,letter "]") t))
                                  nil)
                                 (`(priority ,comparator ,letter)