Filip Roséen authored Mar 23, 2017 and Jean-Baptiste Kempf committed Mar 27, 2017

The changes introduced in 36bee770

 had the unfortunate side-effect that
location-data that could not be parsed as a URL would be discarded,
for example an xspf playlist containing the line below would simply
ignore it (due to ProcessMRL rejecting it):

> dvb-t://frequency=674000000:inversion=-1:bandwidth=8:code-rate-hp=2/3:code-rate-lp=1/2:modulation=64QAM:transmission=8:guard=1/32:

In order to fix the issue while still allowing uri-resolving for
URI-valid entities, the following changes make sure that we retain the
original string if it contains "://" and all prior characters are
valid in a scheme.

fixes: #18155

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>