Fix eslint no-irregular-whitespace in percent_space format

Replace non-breaking space (U+00A0) with regular space in
percent_space number format template literal. Upstream used
a literal NBSP for French-style typographic spacing.

app/javascript/template_builder/field_settings.vue

@@ -830,7 +830,7 @@ export default {
       } else if (format === 'percent') {
         return `${number}%`
       } else if (format === 'percent_space') {
-        return `${String(number).replace('.', ',')} %`
+        return `${String(number).replace('.', ',')} %`
       } else {
         return number
       }