Removed unneeded check [skip ci]

src/vector.c

@@ -270,11 +270,6 @@ vector_in(PG_FUNCTION_ARGS)
 				 errmsg("invalid input syntax for type vector: \"%s\"", lit),
 				 errdetail("Junk after closing right brace.")));
 
-	if (dim < 1)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATA_EXCEPTION),
-				 errmsg("vector must have at least 1 dimension")));
-
 	CheckDim(dim);
 	CheckExpectedDim(typmod, dim);