beta 3 (#3780)

* merge master - allow to upload twig invoice templates via UI
* support adding existing teams with same name
* permissions cannot be set right after role was created - fixes #3777
* allow to deactivate unique customer number validation - fixes #3762 
* invalid message when trying to edit locked or exported timesheets in calendar - fixes #3766
* updated icons and manifest - fixes #3761

src/Controller/SystemConfigurationController.php

@@ -432,6 +432,7 @@ final class SystemConfigurationController extends AbstractController
                         ])
                         ->setRequired(true)
                         ->setType(TextType::class)
+                        ->setConstraints([new NotBlank()])
                         ->setTranslationDomain('system-configuration'),
                 ]),
             $authentication,
@@ -459,6 +460,10 @@ final class SystemConfigurationController extends AbstractController
                         ->setRequired(true)
                         ->setType(TextType::class)
                         ->setTranslationDomain('system-configuration'),
+                    (new Configuration('customer.rules.allow_duplicate_number'))
+                        ->setLabel('customer.allow_duplicate_number')
+                        ->setType(YesNoType::class)
+                        ->setTranslationDomain('system-configuration'),
                 ]),
             (new SystemConfigurationModel('project'))
                 ->setConfiguration([