update theme

diff --git a/themes/plain b/themes/plain
index 6d75fac94800a6d96075b17931cab2a8ff5bf503..1c01094c67cf50dff0b140a672ba339c582ce2c5 160000 (submodule)
--- a/themes/plain
+++ b/themes/plain
@@ -1 +1 @@
-Subproject commit 6d75fac94800a6d96075b17931cab2a8ff5bf503
+Subproject commit 1c01094c67cf50dff0b140a672ba339c582ce2c5