windowthumbnail 'count > 0' is always true
Fix PVS-Studio issue "src/declarativeimports/core/windowthumbnail.cpp:813: warning: V547 Expression 'count > 0' is always true."
Fix PVS-Studio issue "src/declarativeimports/core/windowthumbnail.cpp:813: warning: V547 Expression 'count > 0' is always true."