Correct character in description of glyph widths

A previous change, I2c0f0365824caef6959b213ddae5a03f8cf62c7c,
mistakenly listed a comma for the codepoint U+002E. The correct
character is a full stop.

Test: none
Change-Id: I9121473d7332f8ffd29f304fe19291d35d3cb1aa
1 file changed