Revert "GIT_SILENT: minor qstring optimization"

This reverts commit f96deb39.

This was anti-optimization.

• QStringLiteral is a QString created at build time. Initialization of QString with it has no overhead.
• QLatin1String is 8 bit C string wrapper which needs run-time conversion to 16 bit encoding used in QString.

References:

• https://doc.qt.io/qt-5/qstring.html#more-efficient-string-construction
• https://doc.qt.io/qt-5/qlatin1string.html#details (note at the end of the section)

For some reason this was commited without review and with GIT_SILENT.