pagevideos: Prevent renaming video if file name prefix is already used
This prevents some issues and weirdnesses with losing the video thumbnail, etc.
<RCC>
<qresource prefix="/">
<file>main.qml</file>
<file>Page1.qml</file>
<file>Page1Form.ui.qml</file>
<file>qtquickcontrols2.conf</file>
<file>res/iconTime.png</file>
</qresource>
</RCC>