Bump swiftmailer/swiftmailer from 6.2.5 to 6.2.7

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

diff --git a/3rdparty b/3rdparty
index d984340ba2d63bac9cc121a0b6e0d664bcc0ef09..5738208c3213ff818c69a144cde23bd64554f5c8 160000 (submodule)
--- a/3rdparty
+++ b/3rdparty
@@ -1 +1 @@
-Subproject commit d984340ba2d63bac9cc121a0b6e0d664bcc0ef09
+Subproject commit 5738208c3213ff818c69a144cde23bd64554f5c8