Fix search input margin

Before: https://www.dropbox.com/s/ppif4opa904m91k/broken_search2.png

After: https://www.dropbox.com/s/bxy065pzch39bg1/broken_search.png

Currently, the margin of the search input messes up the border line.
Merge pull request #494 from pawl/patch-5

Fix search input margin