d/rules: drop override_dh_shlibdeps

No longer needed. As stated in the dh_shlibdeps manpage,
the tool is now smarter and doesn't require the options in our override.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>

debian/rules

@@ -7,10 +7,6 @@ LIB_DIR := /usr/lib/$(DEB_HOST_MULTIARCH)
 
 _dhopts := --with autoreconf
 
-_shlibdeps := \
-  -a -X$(LIB_DIR) \
-  -l$(CURDIR)/debian/build/extensions/.libs
-
 _configure := \
   --disable-libipq \
   --enable-devel \
@@ -21,8 +17,5 @@ _configure := \
 %:
 	dh $@ $(_dhopts)
 
-override_dh_shlibdeps:
-	dh_shlibdeps $(_shlibdeps)
-
 override_dh_auto_configure:
 	dh_auto_configure -- $(_configure)