Do not force viewport attributes' minimumScale value
[Title] Do not force viewport attributes' minimumScale value.
[Issue#] N/A
[Problem] Viewport attributes' minimumScale is forced by contents' width.
[Cause] minimumScale is recalculated by contents' width if it exceeds layout width
[Solution] Do not force minimumScale when userScalable is false.
This patch is pre-merged into webkit2-release-0.7
http://slp-info.sec.samsung.net/gerrit/#change,86755
Change-Id: I60c97053b94f486a14e160672c6da611e31a1607