Fix wrong spectrum data for element Zn

The spectra for Cu and Zn are identical.

According to this mailing list thread
http://sourceforge.net/p/blueobelisk/mailman/blueobelisk-discuss/thread/200509131057.41032.cniehaus@gmx.de/#msg3557940
this is the source reference for the spectra data:
http://physics.nist.gov/PhysRefData/Handbook/element_name_a.htm

The spectral data for copper CU seem to be ok, see
http://physics.nist.gov/PhysRefData/Handbook/Tables/coppertable3_a.htm
but the data for zinc Zn are obviously wrong, see
http://physics.nist.gov/PhysRefData/Handbook/Tables/zinctable3_a.htm

BUG:339271
REVIEW:120651
FIXED-IN:4.14.3