INITIALIZE with refmod => handle field as alphanumeric

debug output:

$ initialize_statement=1 gcobol $flags -oo gcc/cobol/gcobol-tests/testsuite.dir/$T/*.cob -Wl,-rpath=$libgcobol 2>&1 | grep initialize_statement && ./o
[...]
cobol1: initialize_statement: 1 targets, no filler, category_none, to_default=no
        initialize_statement: MY-OTHER-FLD
cobol1: initialize_statement: 9311: N=0 MY-OTHER-FLD     FldNumericDisplay
cobol1: initialize_statement:SPACES: 01 MY-OTHER-FLD         P  0             0{  4,4,0 = ZEROS} 0x0000, line 7

runtime output:

MY-OTHER-FLD: 0000

It seems parser_move(target, SPACES) sets FldNumericDisplay to zeros even if target has a refmod.