Manual cherry-pick from #1111

This hsould merge still-valid piece of #1111 into master.

include/internal/catch_context.cpp

@@ -20,7 +20,7 @@ namespace Catch {
             return m_runner;
         }
 
-        virtual IConfigPtr getConfig() const override {
+        virtual IConfigPtr const& getConfig() const override {
             return m_config;
         }