config: fix location of completion-{delay,popover} in default config

The default config had completion-{delay,popover} in the [viewer]
section, but they belong in the [ui] section

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>
Acked-by: Robin Jarry <robin@jarry.cc>

config/aerc.conf

@@ -145,6 +145,17 @@ styleset-name=default
 #   consecutive characters in the command or option.
 #fuzzy-complete=false
 
+# How long to wait after the last input before auto-completion is triggered.
+#
+# Default: 250ms
+completion-delay=250ms
+
+#
+# Global switch for completion popovers
+#
+# Default: true
+completion-popovers=true
+
 #[ui:account=foo]
 #
 # Enable threading in the ui. Only works with notmuch:// and imap:// accounts
@@ -215,17 +226,6 @@ always-show-mime=false
 # Default: true
 parse-http-links=true
 
-# How long to wait after the last input before auto-completion is triggered.
-#
-# Default: 250ms
-completion-delay=250ms
-
-#
-# Global switch for completion popovers
-#
-# Default: true
-completion-popovers=true
-
 [compose]
 #
 # Specifies the command to run the editor with. It will be shown in an embedded