putting the slack config in the right place

Change-Id: I0e2dc75403baba0aa84c6b3db24070253d156483
diff --git a/jenkins.plugins.slack.webhook.GlobalConfig.xml b/.jenkins/jenkins.plugins.slack.webhook.GlobalConfig.xml
similarity index 100%
rename from jenkins.plugins.slack.webhook.GlobalConfig.xml
rename to .jenkins/jenkins.plugins.slack.webhook.GlobalConfig.xml