Removing @INSTALL_STRIP@ prevents stripping of debuginfo at %install time

Cleaning up top_srcdir prevents debuginfo package creation fails like this:

/usr/lib/rpm/debugedit: canonicalization unexpectedly shrank by one character

--- proftpd-1.3.2rc3/Make.rules.in	2009-01-08 16:54:26.000000000 +0000

+++ proftpd-1.3.2rc3/Make.rules.in	2009-01-08 16:54:48.000000000 +0000

@@ -29,8 +29,8 @@

 INSTALL=@INSTALL@

 INSTALL_USER=@install_user@

 INSTALL_GROUP=@install_group@

-INSTALL_BIN=$(INSTALL) @INSTALL_STRIP@ -o $(INSTALL_USER) -g $(INSTALL_GROUP) -m 0755

-INSTALL_SBIN=$(INSTALL) @INSTALL_STRIP@ -o $(INSTALL_USER) -g $(INSTALL_GROUP) -m 0755

+INSTALL_BIN=$(INSTALL) -o $(INSTALL_USER) -g $(INSTALL_GROUP) -m 0755

+INSTALL_SBIN=$(INSTALL) -o $(INSTALL_USER) -g $(INSTALL_GROUP) -m 0755

 INSTALL_MAN=$(INSTALL) -o $(INSTALL_USER) -g $(INSTALL_GROUP) -m 0644

 RM=rm -f

--- proftpd-1.3.2rc3/contrib/mod_load/Makefile.in	2008-09-08 21:56:02.000000000 +0100

+++ proftpd-1.3.2rc3/contrib/mod_load/Makefile.in	2009-01-08 20:37:26.000000000 +0000

@@ -1,5 +1,5 @@

 top_builddir=../..

-top_srcdir=../../

+top_srcdir=../..

 srcdir=@srcdir@

 include $(top_srcdir)/Make.rules

--- proftpd-1.3.2rc3/contrib/mod_wrap2/Makefile.in	2008-09-08 21:56:02.000000000 +0100

+++ proftpd-1.3.2rc3/contrib/mod_wrap2/Makefile.in	2009-07-03 17:00:41.000000000 +0100

@@ -1,5 +1,5 @@

 top_builddir=../..

-top_srcdir=../../

+top_srcdir=../..

 srcdir=@srcdir@

 include $(top_srcdir)/Make.rules