Fix header button height

Apparently, production environments need this for openstreetmap#6988 to be seamless

Author: hlfan

app/views/layouts/_select_language_button.html.erb

@@ -2,6 +2,6 @@
 
 <%= tag.button tag.i(:class => "bi bi-translate fs-5 lh-1"),
                :type => "button",
-               :class => ["btn btn-outline-secondary align-self-stretch px-2", *extra_classes],
+               :class => ["btn btn-outline-secondary align-self-stretch py-0 px-2", *extra_classes],
                :title => t(".title"),
                :data => { :bs_toggle => "modal", :bs_target => "#select_language_dialog" } %>