Fix TypeError in item-picker on chart reload

Fixes:

```
smart-select-class.js:105 Uncaught TypeError: Cannot read properties of undefined (reading 'options')
    at HTMLInputElement.handleInputChange (smart-select-class.js:105:41)
    at HTMLDivElement.handleLiveEvent (dom7.module.js:320:48)
```

Signed-off-by: Florian Hotze <[email protected]>

Author: florian-h05

bundles/org.openhab.ui/web/src/pages/analyzer/analyzer.vue

@@ -38,7 +38,8 @@
         <f7-block class="no-margin no-padding" v-show="controlsTab === 'series'">
           <f7-row>
             <f7-col :width="100" />
-            <f7-col :width="100" v-if="showChart">
+            <!-- use v-show instead of v-if to keep the item-picker props valid while selecting Items and avoid TypeErrors -->
+            <f7-col :width="100" v-show="showChart">
               <div class="card data-table">
                 <div class="card-header no-padding" style="min-height: auto">
                   <f7-list style="width: 100%">