docs: fix version output in demo

Author: dangreen

examples/buildDemo.js

@@ -134,15 +134,15 @@ function renderUserAgentRegex({
   let regexBrowsersVersion = ''
 
   if (minVersion) {
-    regexBrowsersVersion = minVersion.join('.')
+    regexBrowsersVersion = minVersion.filter(isFinite).join('.')
   } else {
     regexBrowsersVersion = '...'
   }
 
   regexBrowsersVersion += ' - '
 
   if (maxVersion) {
-    regexBrowsersVersion += maxVersion.join('.')
+    regexBrowsersVersion += maxVersion.filter(isFinite).join('.')
   } else {
     regexBrowsersVersion += '...'
   }