[FIX] lineHeightMultiple is ignored.

The lineHeightMultiple is effectively ignored unless minimumLineHeight or maximumLineHeight are set for decreasing or increasing the line height respectively. This was introduced in an attempt to fix [Issue #314] (see [Commit #871b932]). The ternary operator applied the multiple to the wrong side of the result.
Merge pull request #373 from kevinoneill/master

[FIX] lineHeightMultiple is ignored.