add explicit BR for the gcc compiler

... as instructed at:

https://fedoraproject.org/wiki/Packaging:C_and_C%2B%2B

nano.spec

@@ -1,7 +1,7 @@
 Summary:         A small text editor
 Name:            nano
 Version:         2.9.3
-Release:         2%{?dist}
+Release:         3%{?dist}
 License:         GPLv3+
 URL:             https://www.nano-editor.org
 Source:          https://www.nano-editor.org/dist/v2.9/%{name}-%{version}.tar.gz
@@ -9,6 +9,7 @@ Source2:         nanorc
 
 BuildRequires:   file-devel
 BuildRequires:   gettext-devel
+BuildRequires:   gcc
 BuildRequires:   git
 BuildRequires:   groff
 BuildRequires:   ncurses-devel
@@ -79,6 +80,9 @@ exit 0
 %{_datadir}/nano
 
 %changelog
+* Mon Feb 19 2018 Kamil Dudka <kdudka@redhat.com> - 2.9.3-3
+- add explicit BR for the gcc compiler
+
 * Thu Feb 08 2018 Fedora Release Engineering <releng@fedoraproject.org> - 2.9.3-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild