WebApp: Addding Source Control may fail intermittently if the request is sent while the SCM\Kudu WebSite is restarting.

## Issue Description:
The customer is using the Azure Management Libraries for Java to create a Function App.

``` oSvcMgr = m_oCliLong.appServices();
oFctApps = oSvcMgr.functionApps();
oFctApp = oFctApps.define(zFctID)
.withRegion(AzureDefs.AZURE_REGION)
.withNewResourceGroup(zResGroup)
.withPlatformArchitecture(PlatformArchitecture.X64)
.withNetFrameworkVersion(NetFrameworkVersion.V4_6)
.withAppSettings(oAzureEnv)
.defineSourceControl()
.withPublicGitRepository(AzureDefs.AZURE_FUNCTION_GITHUB_URL)
.withBranch("master")
.attach()
.defineAuthentication()
.withAnonymousAuthentication()
.attach()
.create();

if (oFctApp == null)
{
s_oLog.error("AzureFunction::createFunction Cannot create function [" + zFctID + "]");
return (false);
}
```

## Expected Result
That the Function App be configured with the Git repository.

## Actual Result
The Function App is created but without the Source Control information.

## Issue Details

While the Azure App Service Function App is being provisioned there is a time when the request to Update the Source Control may return a 500 Server error while the Site is restarting. The normal response is a 204.

This issue is opened to see if the Management Libraries can be more resilient in attempting this operation.