Make source URL compatible with release candidates

matrix-synapse.spec

@@ -1,5 +1,8 @@
 %global srcname synapse
 
+# Version suffix in URL when building release candidates
+%global rcx %{nil}
+
 %{?python_enable_dependency_generator}
 
 Name:       matrix-%{srcname}
@@ -8,7 +11,7 @@ Release:    2%{?dist}
 Summary:    A Matrix reference homeserver written in Python using Twisted
 License:    ASL 2.0
 URL:        https://github.com/matrix-org/%{srcname}
-Source0:    %{url}/archive/v%{version}/%{srcname}-%{version}.tar.gz
+Source0:    %{url}/archive/v%{version}%{rcx}/%{srcname}-%{version}%{rcx}.tar.gz
 Source1:    synapse.sysconfig
 Source2:    synapse.service
 BuildArch:  noarch
@@ -71,7 +74,7 @@ the ecosystem.
 
 
 %prep
-%autosetup -p1 -n %{srcname}-%{version}
+%autosetup -p1 -n %{srcname}-%{version}%{rcx}
 
 # We don't support the built-in client so remove all the bundled JS.
 rm -rf synapse/static