Use latest xml-conduit.

pandoc.cabal

@@ -492,7 +492,7 @@ library
                  unicode-transforms    >= 0.3      && < 0.4,
                  unordered-containers  >= 0.2      && < 0.3,
                  xml                   >= 1.3.12   && < 1.4,
-                 xml-conduit           >= 1.7      && < 1.10,
+                 xml-conduit           >= 1.9.1.1  && < 1.10,
                  zip-archive           >= 0.2.3.4  && < 0.5,
                  zlib                  >= 0.5      && < 0.7
   if os(windows) && arch(i386)

stack.yaml

@@ -16,6 +16,7 @@ extra-deps:
 - citeproc-0.3.0.9
 - texmath-0.12.2
 - random-1.2.0
+- xml-conduit-1.9.1.1
 ghc-options:
    "$locals": -fhide-source-paths -Wno-missing-home-modules
 resolver: lts-17.5