Enforce doubled refresh rate

resolves #966

src/process.cpp

@@ -284,6 +284,10 @@ namespace proc {
           target_fps *= 1000;
         }
 
+        if (config::video.double_refreshrate) {
+          target_fps *= 2;
+        }
+
         std::wstring vdisplayName = VDISPLAY::createVirtualDisplay(
           device_uuid_str.c_str(),
           device_name.c_str(),
@@ -293,10 +297,6 @@ namespace proc {
           launch_session->display_guid
         );
 
-        if (config::video.double_refreshrate) {
-          target_fps *= 2;
-        }
-
         // No matter we get the display name or not, the virtual display might still be created.
         // We need to track it properly to remove the display when the session terminates.
         launch_session->virtual_display = true;