dev-haskell/cabal-install: fixed metadata.xml escaping

repoman fails as:
  metadata.bad [fatal]          1
   dev-haskell/cabal-install/metadata.xml: xmlParseEntityRef:
   no name, line 18, column 67 (metadata.xml, line 18)

It's caused by unescaped '&' char in:
  <flag name="native-dns">Enable use of the resolv & windns
  packages for performing DNS lookups.</flag>

Reported-by:  Michał Górny
Closes: https://bugs.gentoo.org/653060
Package-Manager: Portage-2.3.28, Repoman-2.3.9

dev-haskell/cabal-install/metadata.xml

@@ -14,8 +14,8 @@
 		<flag name="noprefs">Ignore 'preferred-versions' file from hackage's tarball.</flag>
 		<flag name="network-uri">Get Network.URI from the network-uri package.</flag>
 		<flag name="parsec">Use parser written in parsec
-                library.</flag>
-                <flag name="native-dns">Enable use of the resolv & windns
-                packages for performing DNS lookups.</flag>
+		library.</flag>
+		<flag name="native-dns">Enable use of the resolv and windns
+		packages for performing DNS lookups.</flag>
 	</use>
 </pkgmetadata>