configure: use pkg-config to detect libbluray

The current configure fails when static libbluray is compiled with libxml2
support.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit baa650cc7946a9eb1cf5a083f61a581a97122f03)
Signed-off-by: Timothy Gu <timothygu99@gmail.com>

Conflicts:
	configure
diff --git a/configure b/configure
index 6585e46..66112bf 100755
--- a/configure
+++ b/configure
@@ -3212,7 +3212,7 @@
 enabled gnutls     && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
 enabled libaacplus && require  "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
 enabled libass     && require_pkg_config libass ass/ass.h ass_library_init
-enabled libbluray  && require libbluray libbluray/bluray.h bd_open -lbluray
+enabled libbluray  && require_pkg_config libbluray libbluray/bluray.h bd_open
 enabled libcelt    && require libcelt celt/celt.h celt_decode -lcelt0 &&
                       { check_lib celt/celt.h celt_decoder_create_custom -lcelt0 ||
                         die "ERROR: libcelt version must be >= 0.11.0."; }