tests: webui: Load qunit only once

webui unit tests fail with grunt-contrib-qunit:
```
Testing test/all_tests.html

>> Error: Error: QUnit has already been defined.
>>     at exportQUnit (file:///home/test/freeipa/install/ui/js/qunit.js:2475:12)
>>     at file:///home/test/freeipa/install/ui/js/qunit.js:2946:3
>>     at file:///home/test/freeipa/install/ui/js/qunit.js:5061:2

>> Error: TypeError: Cannot set properties of undefined (setting 'reorder')
>>     at <anonymous>:175:24
>>     at runFactory (file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:17157)
>>     at execModule (file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:19541)
>>     at file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:20002
>>     at guardCheckComplete (file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:19707)
>>     at checkComplete (file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:19854)
>>     at onLoadCallback (file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:22296)
>>     at HTMLScriptElement.onLoad (file:///home/test/freeipa/install/ui/js/dojo/dojo.js:1:26209)
```

Load `qunit` with `dojo.require` that among other useful things helps
> Preventing loading Dojo packages twice.
  dojo.require will simply return if the package is already loaded.

See also https://github.com/gruntjs/grunt-contrib-qunit#loading-qunit-with-amd

Related: https://pagure.io/freeipa/issue/9329
Signed-off-by: Stanislav Levin <[email protected]>

install/ui/test/all_tests.html

@@ -6,23 +6,14 @@
 
  <script type="text/javascript" src="../js/libs/loader.js"></script>
  <script type="text/javascript" src="../js/libs/jquery.js"></script>
- <script>
- // import qunit.js only in situations it is not imported by grunt-contrib-qunit
- // allows to run tests using grunt and using Firefox (FF needs explicit import)
- if (window.QUnit === undefined) {
- var s = document.createElement("script");
- s.type = "text/javascript";
- s.src = "qunit.js";
- $("head script:last-of-type").before(s); // insert qunit.js import before dojo import
- }
- </script>
  <script type="text/javascript" src="../js/libs/jquery.ordered-map.js"></script>
  <script type="text/javascript" src="../js/libs/bootstrap.js"></script>
  <script type="text/javascript" src="config.js"></script>
- <script class='insertBefore' type="text/javascript" src="../js/dojo/dojo.js"></script>
+ <script type="text/javascript" src="../js/dojo/dojo.js"></script>
 
  <script type="text/javascript">
  require([
+ 'qunit',
  'test/ordered_map_tests',
  'test/ipa_tests',
  'test/details_tests',
@@ -36,7 +27,7 @@
  'test/build_tests',
  'test/binding_tests',
  'test/topology_tests',
- ], function(om, ipa, details, entity, as, cert, aci, wid, ip, ut, bt, bi, topo){
+ ], function(qunit, om, ipa, details, entity, as, cert, aci, wid, ip, ut, bt, bi, topo){
  QUnit.start();
  om();
  ipa();