Fix linking error of app for iOS in optimized build
Fix linking error of app for iOS in optimized build

ShowLockedDocumentDialog uses the DocumentLockFile API which is not
compiled for non-desktop OSes (see svl/Library_svl.mk). This leads to
an undefined reference to svt::DocumentLockFile::m_bAllowInteraction.
As ShowLockedDocumentDialog isn't used anyway without
HAVE_FEATURE_MULTIUSER_ENVIRONMENT, put it inside such an #if, too.

Thanks to Tsahi Glik <tsahi.glik@cloudon.com> for noticing.

Change-Id: I45d2179395b44709c52ab1871866a2bd5720c8b6

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core