Update stardust-gravity.spec

Unify summaries

Signed-off-by: Owen Zimmerman <[email protected]>

anda/stardust/gravity/stardust-gravity.spec

@@ -7,7 +7,7 @@
 Name:           stardust-gravity
 Version:        %commit_date.%shortcommit
 Release:        1%?dist
-Summary:        Utility to launch apps and stardust clients spatially.
+Summary:        Utility to launch apps and Stardust XR clients spatially.
 URL:            https://github.com/StardustXR/gravity
 Source0:        %url/archive/%commit/gravity-%commit.tar.gz
 License:        MIT