[tracker] build: Change configure's --disable-libxml2 to --enable-libxml2, like others.

[Martyn James Russell <mr src gnome org>]

commit 47c2852f6e10e087bf0fd78c5a222f181a33eaf2
Author: Martyn Russell <martyn lanedo com>
Date:   Wed Feb 26 15:14:55 2014 +0000

    build: Change configure's --disable-libxml2 to --enable-libxml2, like others.
    
    Nothing changes as a result of this, the default is still to enable by
    default.

 configure.ac |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f6ebc90..aa5b97c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1502,8 +1502,8 @@ AM_CONDITIONAL(HAVE_LIBSTREAMANALYZER, test "$have_libstreamanalyzer" = "yes")
 ##################################################################
 
 AC_ARG_ENABLE(libxml2,
-              AS_HELP_STRING([--disable-libxml2],
-                             [disable HTML/XML extractors [[default=yes]]]),,
+              AS_HELP_STRING([--enable-libxml2],
+                             [enable extractor for HTML/XML metadata [[default=yes]]]),,
               [enable_libxml2=yes])
 
 # Force libxml requirement for HAVE_MAEMO,