[G12] Please correct this in the build

[Michael C. Kunkel]

Greetings,

For those that maintain builds, please change the following lines of 
code in clasEvent.cc

In function
threeVec clasParticle::ECxyz2uvw()
line 3556 in the standard build
line 3576 in the Paolones build

w = 0.5*((2.0*yhi-ylow-yi)/tgrho - xi)/cosrho;
to
w=((yhi-ylow)/tgrho + xi + (yhi-yi)/tgrho)/2./cosrho;

This will return the correct w coordinate.

BR
MK