minor fix to http basic auth (#5839)

Author: wing328

modules/openapi-generator/src/main/resources/powershell-experimental/api.mustache

@@ -179,7 +179,7 @@ function {{{vendorExtensions.x-powershell-method-name}}} {
         {{/isKeyInCookie}}
         {{/isApiKey}}
         {{#isBasicBasic}}
-        if ($Configuration["Username"] -and $Configuration["Password"]]) {
+        if ($Configuration["Username"] -and $Configuration["Password"]) {
             $LocalVarBytes = [System.Text.Encoding]::UTF8.GetBytes($Configuration["Username"] + ":" + $Configuration["Password"])
             $LocalVarBase64Text =[Convert]::ToBase64String($LocalVarBytes)
             $LocalVarHeaderParameters['Authorization'] = "Basic " + $LocalVarBase64Text