FIX: don't treat zero value in mold/part as unlimited output

Reverted change from e108cfc

Author: Oldes

src/boot/sysobj.reb

@@ -149,7 +149,7 @@ options: object [  ; Options supplied to REBOL during startup
 
 	binary-base: 16    ; Default base for FORMed binary values (64, 16, 2)
 	decimal-digits: 15 ; Max number of decimal digits to print.
-	probe-limit: 16000 ; Max probed output size, 0 means no limit
+	probe-limit: 16000 ; Max probed output size
 	module-paths: [%./]
 	default-suffix: %.reb ; Used by IMPORT if no suffix is provided
 	file-types: []

src/core/n-io.c

@@ -139,7 +139,7 @@ static REBSER *Read_All_File(char *fname)
 		if (VAL_INT64(D_ARG(6)) > (i64)MAX_I32)
 			len = MAX_I32;
 		else if (VAL_INT64(D_ARG(6)) <= 0)
-			len = NO_LIMIT;
+			len = 0;
 		else
 			len = VAL_INT32(D_ARG(6));
 	}