Add gcc buildrequires

This package compiles C code, so should directly depend on a C compiler.
Also remove setting CFLAGS to %optflags, since the %configure macro
already does that for us.

libnsl2.spec

@@ -4,7 +4,7 @@
 
 Name:       libnsl2
 Version:    1.3.0
-Release:    2%{?dist}
+Release:    3%{?dist}
 Summary:    Public client interface library for NIS(YP) and NIS+
 
 License:    BSD and LGPLv2+
@@ -17,6 +17,7 @@ Patch0: libnsl2-1.0.5-include_stdint.patch
 
 BuildRequires: autoconf, automake, gettext-devel, libtool, libtirpc-devel
 BuildRequires: make
+BuildRequires: gcc
 
 %description
 This package contains the libnsl library. This library contains
@@ -39,9 +40,6 @@ Development files for libnsl2
 %patch0 -p1 -b .include_stdint
 
 %build
-
-export CFLAGS="%{optflags}"
-
 autoreconf -fiv
 
 %configure\
@@ -69,6 +67,10 @@ rm %{buildroot}/%{_libdir}/libnsl.la
 %{_libdir}/pkgconfig/libnsl.pc
 
 %changelog
+* Thu May 20 2021 Timm Bäder <tbaeder@redhat.com> - 1.3.0-3
+- Add gcc buildrequires
+- Remove explicit setting of CFLAGS
+
 * Tue Jan 26 2021 Fedora Release Engineering <releng@fedoraproject.org> - 1.3.0-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild