Do not BR re2c on RHEL. It is NTH, and one less package dep to maintain

ninja-build.spec

@@ -4,7 +4,7 @@
 
 Name:           ninja-build
 Version:        1.10.2
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        Small build system with a focus on speed
 License:        ASL 2.0
 URL:            https://ninja-build.org/
@@ -17,7 +17,9 @@ BuildRequires:  python3-devel
 BuildRequires:  asciidoc
 BuildRequires:  gtest-devel
 %endif
+%if !0%{?rhel}
 BuildRequires:  re2c >= 0.11.3
+%endif
 %if %{without bootstrap}
 Requires:       emacs-filesystem
 Requires:       vim-filesystem
@@ -84,6 +86,9 @@ ln -s ninja %{buildroot}%{_bindir}/ninja-build
 %{_rpmmacrodir}/macros.ninja
 
 %changelog
+* Tue May 04 2021 Richard Hughes <rhughes@redhat.com> - 1.10.2-4
+- Do not BR re2c on RHEL. It is NTH, and one less package dep to maintain.
+
 * Fri Mar 05 2021 Igor Raits <ignatenkobrain@fedoraproject.org> - 1.10.2-3
 - Cleanup from unneeded conditions