Fix repeater range step and stop (openhab#3440)

Fixes two small issues when using the `sourceType: range` of oh-repeater.

1) step values less than one or with decimal components improperly
calculate number of elements in the final array (go beyond stop value to
next whole number).

2) stop value cannot be set to 0 (falsy value results in default value
of 10 for stop).

Signed-off-by: Justin Georgi <justin.georgi@gmail.com>

Author: JustinGeorgi

bundles/org.openhab.ui/web/src/components/widgets/system/oh-repeater.vue

@@ -91,9 +91,9 @@ export default {
       let sourceResult
       if (this.config.sourceType === 'range') {
         const start = this.config.rangeStart || 0
-        const stop = this.config.rangeStop || 10
+        const stop = isNaN(this.config.rangeStop) ? 10 : this.config.rangeStop
         const step = this.config.rangeStep || 1
-        sourceResult = Promise.resolve(Array(Math.ceil((stop + 1 - start) / step)).fill(start).map((x, y) => x + y * step))
+        sourceResult = Promise.resolve(Array(Math.floor((stop + step - start) / step)).fill(start).map((x, y) => x + y * step))
       } else if (this.config.sourceType === 'itemsWithTags' && this.config.itemTags) {
         sourceResult = this.$oh.api.get('/rest/items?metadata=' + this.config.fetchMetadata + '&tags=' + this.config.itemTags).then((d) => Promise.resolve(d.sort(compareItems)))
         this.sourceCache = (this.config.cacheSource) ? sourceResult : null