Rename script due to a name clash on macosx

There are two files pl_Eff_XY.C and pl_eff_XY.C in the directory macro/beamtime which result in problems on macosx with upper-/lowercase distinction. To solve the issue rename pl_Eff_XY.C to pl_Eff_XY_1.C. Correct the function name.

mentioned in merge request !142 (merged)

Pinging @n.herrmann as probably some macros/scripts will need updates t probably load the modified one

merged