Remove redundant rule from print styles

Normalize.css is already setting the margin on the body element to 0
[1], so there's no need to do the same in the print styles.

[1] https://github.com/necolas/normalize.css/blob/fc091cce1534909334c1911709a39c22d406977b/normalize.css#L24C4-L25C2

Author: smfeest

src/Buttercup.Web/styles/print.less

@@ -1,7 +1,3 @@
-body {
-  margin: 0;
-}
-
 h1 {
   text-align: center;
 }