Fix: (link) Allow brackets in description

Org 9.3 stopped replacing brackets in link descriptions with braces
and started escaping them instead.

Fixes #283.  Thanks to Daniel Borchmann (@exot) for reporting.

org-ql.info

@@ -1055,6 +1055,9 @@ File: README.info,  Node: 07-pre,  Next: 063,  Up: Changelog
      (Thanks to Akira Komamura (https://github.com/akirak).)
 
    *Fixed*
+   • Predicate ‘link’ matches links whose descriptions contain escaped
+     brackets (changed in Org 9.3).  (Thanks to Daniel Borchmann
+     (https://github.com/exot) for reporting.)
    • Predicate ‘src’’s matching of begin/end block lines, normalization
      of arguments, and handling in non-sexp queries.  (Thanks to Akira
      Komamura (https://github.com/akirak) for reporting.)
@@ -1735,35 +1738,35 @@ Node: Links37255
 Node: Tips37942
 Node: Changelog38266
 Node: 07-pre39049
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-Node: 0259995
-Node: 0164073
-Node: Notes64174
-Node: Comparison with Org Agenda searches64336
-Node: org-sidebar65225
-Node: License65504
+Node: 06341973
+Node: 06242508
+Node: 06142813
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+Node: 0260184
+Node: 0164262
+Node: Notes64363
+Node: Comparison with Org Agenda searches64525
+Node: org-sidebar65414
+Node: License65693
 
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