fix(NcModal): Adjust max height to leave some space

This is so that the modal doesn't exactly touch the edges of the header, which looks a bit weird.

Signed-off-by: Laura Kramolis <git@kramo.page>
Signed-off-by: kramo <git@kramo.page>

Author: kra-mo

src/components/NcModal/NcModal.vue

@@ -733,7 +733,7 @@ function clearFocusTrap() {
 
 	// We allow 90% max-height, but we need to ensure the header does not overlap the modal
 	// as the modal is centered, we need the space on top and bottom
-	$max-modal-height: min(90%, calc(100% - 2 * var(--header-height)));
+	$max-modal-height: min(90%, calc(100% - 2 * var(--header-height) - 2 * var(--body-container-margin)));
 
 	// Sizing
 	&--small {