rpm: remove libstrophe.spec

Major Linux distributions have added libstrophe to their repositories.
We don't have to support our own spec file. If someone needs spec to
build rpm manually, refer to Linux distributions, for example:

https://build.opensuse.org/package/show/network/libstrophe
https://copr-dist-git.fedorainfracloud.org/cgit/linkdupont/fedora-link-extras/libstrophe.git

rpm/README

@@ -1,31 +0,0 @@
-1. Setup
-
-yum install gcc make autoconf automake expat-devel openssl-devel
-
-Fedora:
-
-yum install fedora-packager
-cd ~
-rpmdev-setuptree
-
-CentOS:
-
-mkdir -p ~/rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
-
-Then make a tarball of sources:
-
-tar czf libstrophe_git.tar.gz libstrophe
-
-2. Build
-
-cp libstrophe.spec ~/rpmbuild/SPECS
-cp libstrophe_git.tar.gz ~/rpmbuild/SOURCES
-rpmbuild -bb ~/rpmbuild/SPECS/libstrophe.spec
-
-3. Install
-
-yum localinstall ~/rpmbuild/RPMS/<arch>/libstrophe-1.1<dist>.<arch>.rpm
-
-Or, if localinstall is not recognised:
-
-rpm -i ~/rpmbuild/RPMS/<arch>/libstrophe-1.1<dist>.<arch>.rpm

rpm/libstrophe.spec

@@ -1,59 +0,0 @@
-Name:		libstrophe
-Version:	1
-Release:	1%{?dist}_git
-Summary:	xmpp library in C
-
-Group:		Application/System
-License:	MIT/GPLv3
-URL:		http://strophe.im/libstrophe/
-Source0:	libstrophe_git.tar.gz
-
-BuildRequires:	autoconf
-BuildRequires:	automake
-BuildRequires:	libtool
-BuildRequires:	openssl-devel
-BuildRequires:	expat-devel
-Requires:	openssl
-Requires:	expat
-
-%description
-XMPP library in C
-
-%package        devel
-Summary:        Headers and libraries for building apps that use libstrophe
-Group:          Development/Libraries
-Requires:       %{name} = %{version}-%{release}
-
-%description    devel
-This package contains headers and libraries required to build applications that
-use the strophe XMPP library.
-
-%prep
-%setup -n libstrophe
-./bootstrap.sh
-
-%build
-%configure
-make %{?_smp_mflags}
-
-%install
-make install DESTDIR=%{buildroot}
-
-%post -p /sbin/ldconfig
-
-%postun -p /sbin/ldconfig
-
-%files
-%defattr(-,root,root,-)
-%{_libdir}/libstrophe.so*
-%doc
-
-%files devel
-%defattr(-,root,root,-)
-%{_libdir}/libstrophe.a
-%{_libdir}/libstrophe.la
-%{_libdir}/pkgconfig/libstrophe.pc
-%{_includedir}/strophe.h
-%doc
-
-%changelog