Unintended "&" in some warning messages

[tueda]

grep -r -n 'Warning("&' sources

prints

sources/names.c:1529:                           Warning("&Excess information in symmetric properties currently ignored");
sources/names.c:1550:                                   Warning("&Illegal information in number of arguments properties currently ignored");
sources/names.c:1574:                                   Warning("&Illegal information in number of arguments properties currently ignored");
sources/module.c:675:                           Warning("&Undefined $-variable in module statement");

These warning messages are not displayed as intended: an unnecessary & character appears in the output. For example,

ModuleOption local,$a;
.end

test.frm Line 1 --> Warning: &Undefined $-variable in module statement