r.series.interp: samplingpos option is multiple (merge from trunk, https://trac.osgeo.org/grass/changeset/60932)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@60933 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.series.interp/main.c

@@ -92,6 +92,7 @@ int main(int argc, char *argv[])
     parm.samplingpos->key = "samplingpos";
     parm.samplingpos->type = TYPE_DOUBLE;
     parm.samplingpos->required = NO;
+    parm.samplingpos->multiple = YES;
     parm.samplingpos->description = _("Sampling point position for each output map");
 
     parm.outfile = G_define_standard_option(G_OPT_F_INPUT);