(sect_has_dock): NAV_CANAL in sect.h rev. 1.36 broke loading in

canals, fix.  Can't enforce M_CANAL condition here, so leave it to
callers.  Callers don't enforce it either, which means landlocked
ships can load in canals.  Oh well.

src/lib/subs/shpsub.c

@@ -398,6 +398,7 @@ sect_has_dock(struct sctstr *sect)
 {
     switch (dchr[sect->sct_type].d_nav) {
     case NAV_02:
+    case NAV_CANAL:
 	return 1;
     default:
 	return 0;