Update version to 17.1.0-rc1

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/VERSION b/VERSION
index dc99675..0bc4493 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-17.1.0-devel
+17.1.0-rc1