[connections] .gitmodules: Use stable branch for submodules

[Felipe Borges <felipeborges src gnome org>]

commit b5e67d780df53e64452b6b3ebf3a6e1c6519ea3e
Author: Felipe Borges <felipeborges gnome org>
Date:   Thu Aug 12 10:56:23 2021 +0200

    .gitmodules: Use stable branch for submodules

 .gitmodules          | 1 +
 subprojects/gtk-frdp | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitmodules b/.gitmodules
index ce36526..12a06fd 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,4 @@
 [submodule "subprojects/gtk-frdp"]
        path = subprojects/gtk-frdp
        url = https://gitlab.gnome.org/gnome/gtk-frdp.git
+       branch = gtk-frdp-0-1
diff --git a/subprojects/gtk-frdp b/subprojects/gtk-frdp
index 805721e..f591dcf 160000
--- a/subprojects/gtk-frdp
+++ b/subprojects/gtk-frdp
@@ -1 +1 @@
-Subproject commit 805721e82ca1df6a50da3b5bd3b75d6747016482
+Subproject commit f591dcf456a1e126c0cdf6e49d436485556d8999