math/mpfr minor change for gcc-4.8.5

[Makoto Fujiwara <makoto%ki.nu@localhost>]

To fix the build problem for gcc 4.8.5,
  http://www.ki.nu/pkgsrc/reports/current/NetBSD-9.0_RC1/20191220.1315/gcc48-4.8.5nb8/build.log

Re:
   https://github.com/NetBSD/pkgsrc/commit/7611affe73d9f7c953878fc9ace71904be552baf#diff-fe42a3075a4b6a6ba583b40054b5ff69

I'll commit attached change on math/mpfr

No objection ?
Thank you,
-- 
Makoto Fujiwara
mef%NetBSD.org@localhost
makoto%if.t.u-tokyo.ac.jp@localhost
Key fingerprint = 0BFA FAEB EAD1 90BA 7498  8F85 6809 9E0B B7EF A12E

Index: math/mpfr/Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/math/mpfr/Makefile,v
retrieving revision 1.41
diff -u -r1.41 Makefile
--- math/mpfr/Makefile	2 Nov 2019 16:16:20 -0000	1.41
+++ math/mpfr/Makefile	22 Dec 2019 00:00:28 -0000
@@ -1,6 +1,7 @@
 # $NetBSD: Makefile,v 1.41 2019/11/02 16:16:20 rillig Exp $
 
 DISTNAME=		mpfr-4.0.2
+PKGREVISION=		1
 CATEGORIES=		math
 MASTER_SITES=		http://www.mpfr.org/${DISTNAME}/
 EXTRACT_SUFX=		.tar.bz2
@@ -12,7 +13,7 @@
 
 .include "../../mk/bsd.prefs.mk"
 GNU_CONFIGURE=		yes
-.if !empty(MACHINE_PLATFORM:MNetBSD-[0-8]*-*) || !empty(MACHINE_PLATFORM:MDragonFly-[0-5]*-*)
+.if !empty(MACHINE_PLATFORM:MNetBSD-[0-9]*-*) || !empty(MACHINE_PLATFORM:MDragonFly-[0-5]*-*)
 CONFIGURE_ARGS+=        --disable-float128
 .endif
 USE_LIBTOOL=		yes