cui: unused code in SvxAreaTabPage::ClickColorHdl_Impl

Once again this is unused since commit
5627d0bdaf1385df9d90dcec3a319c82c089c2ca (Fix #86988#: Redesign of
dialogs, 2001-05-15), and just getting rid of it avoids a crash on
Insert -> Frame -> Area -> Color in Writer.

Change-Id: I4e93b8e5f68c229b3093f60b463bb21173dbd0e5
writerfilter: unused sprmcodetostr*

Change-Id: Ia35b098033c92fdc7d2313d12b01324ef7232b1f