Fix glyph cropping bug

Glyphs were being stored in the glyph cache incorrectly.
The second row of glyphs in any column were being positioned exactly
one pixel too high, causing the preceding glyph in that column to be
cropped, resulting in the reported truncation in some glyphs.

Issue #7003215 Minor UI truncation while reading the mails

Change-Id: I47ce376f78a04d4e07e8b7ed1b3f0b58864c5498