Flymake: Fix second group is not always a digit

Sometimes it is '?'

Ex:
`?:?:Ignored error pattern #^Function apply_filters(_ref_array)? invoked with [34567] parameters, 2 required\.$# was not matched in reported errors.`

Author: hacktivista

flymake-phpstan.el

@@ -69,7 +69,7 @@
                    while (search-forward-regexp
                           (eval-when-compile
                             (rx line-start (1+ (not (any ":"))) ":"
-                                (group-n 1 (one-or-more digit)) ":"
+                                (group-n 1 (one-or-more (not (any ":"))) ":"
                                 (group-n 2 (one-or-more not-newline)) line-end))
                           nil t)
                    for msg = (match-string 2)