install pkgconfig in lib not all

[Michael Tokarev]

The libunbound.pc pkgconfig file is being installed
as part of "all" procedure only. But it is not "all-specific",
it is specific to the libunbound library, and, in particular,
should be installed in --with-libunbound-only build too.
Move installation of this file from install-all to install-lib
target of the Makefile.

Signed-off-by: Michael Tokarev <mjt at tls.msk.ru>

diff --git a/Makefile.in b/Makefile.in
index 55125a44..c907e791 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -573,2 +573,4 @@ install-lib:	lib $(UNBOUND_EVENT_INSTALL)
 	$(INSTALL) -m 755 -d $(DESTDIR)$(mandir)/man3
+	$(INSTALL) -m 755 -d $(DESTDIR)$(libdir)/pkgconfig
+	$(INSTALL) -m 644 contrib/libunbound.pc $(DESTDIR)$(libdir)/pkgconfig
 	$(INSTALL) -c -m 644 doc/libunbound.3 $(DESTDIR)$(mandir)/man3
@@ -594,4 +596,2 @@ install-all:	all $(PYTHONMOD_INSTALL) $(PYUNBOUND_INSTALL) $(UNBOUND_EVENT_INSTA
 	$(INSTALL) -m 755 -d $(DESTDIR)$(mandir)/man1
-	$(INSTALL) -m 755 -d $(DESTDIR)$(libdir)/pkgconfig
-	$(INSTALL) -m 644 contrib/libunbound.pc $(DESTDIR)$(libdir)/pkgconfig
 	$(LIBTOOL) --mode=install cp -f unbound$(EXEEXT) $(DESTDIR)$(sbindir)/unbound$(EXEEXT)