Fix for bug #7335 (https://gna.org/bugs/index.php?7335).
The code which tests that the proton and heteronucleus have not been set to the same atom name has
been moved from the 'self.read()' function to the 'self.vectors()' function. Two more lines of
code, which were placing the atom names into the 'self.relax.data.pdb' data structure were also
identified to cause similar problems and were shifted from the read to the vectors function.
