server: Allow download of system vm templates (#6750)

Currently, ACS does not allow the user to download System VM Templates, even though it may be usefull as it can speed up the registration process of the template for production once the homologation is done beforehand. This PR changes this, allowing the user to download said VM Templates

Co-authored-by: Gabriel Ortiga Fernandes <gabriel.fernandes@scclouds.com.br>

Author: GaOrtiga

server/src/main/java/com/cloud/template/TemplateManagerImpl.java

@@ -522,9 +522,7 @@ private String extract(Account caller, Long templateId, String url, Long zoneId,
             throw new InvalidParameterValueException("Unable to find " + desc + " with id " + templateId);
         }
 
-        if (template.getTemplateType() == Storage.TemplateType.SYSTEM) {
-            throw new InvalidParameterValueException("Unable to extract the " + desc + " " + template.getName() + " as it is a default System template");
-        } else if (template.getTemplateType() == Storage.TemplateType.PERHOST) {
+        if (template.getTemplateType() == Storage.TemplateType.PERHOST) {
             throw new InvalidParameterValueException("Unable to extract the " + desc + " " + template.getName() + " as it resides on host and not on SSVM");
         }