Remove BuildRoot definition

None of currently supported distributions need that.
It was needed last for EL5 which is EOL now

Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>

openconnect.spec

@@ -36,7 +36,6 @@ Source1:	ftp://ftp.infradead.org/pub/openconnect/openconnect-%{version}%{?gitsuf
 Source2:	gpgkey-BE07D9FD54809AB2C4B0FF5F63762CDA67E2F359.asc
 Source3:	macros.gpg
 
-BuildRoot:	%{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
 BuildRequires:	pkgconfig(libxml-2.0) pkgconfig(libpcsclite) krb5-devel gnupg2
 BuildRequires:	autoconf automake libtool python gettext pkgconfig(liblz4)