modify.F: fix bug overwriting crucial parameters from comm.1

[scaedufax]

modify.F containsa bug overwriting N from the namelist input. This leads to errors if a runs is continued, but N has changed during the run (escapers, binaries, ...).

KZ(16) & KZ(17) allow auto-adjustment of values which are overwritten by the namelist input on reruns as well.

This MR changes in modify.F:

• force N from comm.1 on restart.
• Check for auto-adjustment settings KZ(16) and KZ(17) and conditionally restore RMIN, DTMIN, ECLOSE, ETAI, ETAR and ETAU from comm.1 file.
• moved restart parameters WRITE statement below restore segment for correct display of restart parameters.

[spurzem]

Thanks Uli for finding and fixing this.