incorporate upstream patch to address ostream-support-in-sprintf

- use python36-sphinx, and python36-breathe on el7, as python2 is almost
  EOL.
- the incorporated patch addresses the issue of https://github.com/fmtlib/fmt/issues/1631

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

fmt.spec

@@ -1,6 +1,6 @@
 Name:           fmt
 Version:        6.2.0
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        Small, safe and fast formatting library for C++
 
 License:        BSD
@@ -14,6 +14,7 @@ Patch5:         doc-_templates-layout-stripped-download-links.patch
 Patch6:         doc-index-removed-GitHub-iframe.patch
 Patch7:         doc-build-use-sphinx-build-3.patch
 Patch8:         doc-build-use-python3.patch
+Patch9:         fix-ostream-support-in-sprintf.patch
 
 BuildRequires:  gcc
 BuildRequires:  gcc-c++
@@ -26,8 +27,8 @@ BuildRequires:  cmake
 BuildRequires:  doxygen
 BuildRequires:  nodejs-less
 %if 0%{?rhel} && 0%{?rhel} <= 7
-BuildRequires:  python2-sphinx
-BuildRequires:  python2-breathe
+BuildRequires:  python%{python3_version_nodots}-sphinx
+BuildRequires:  python%{python3_version_nodots}-breathe
 %else
 BuildRequires:  python3-sphinx
 BuildRequires:  python3-breathe
@@ -110,6 +111,9 @@ popd
 %license doc/python-license.txt
 
 %changelog
+* Thu Apr 30 2020 Kefu Chai <tchaikov@gmail.com> - 6.2.0-2
+- Incorporate patch from upstream to address https://github.com/fmtlib/fmt/issues/1631
+
 * Mon Apr 06 2020 Vitaly Zaitsev <vitaly@easycoding.org> - 6.2.0-1
 - Updated to version 6.2.0.