Update agent from any to label osm4 in Jenkinsfile

Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/Jenkinsfile b/Jenkinsfile
index daf21e6..0aed286 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -5,7 +5,7 @@
     imagename = "opensourcemano/api-fe"
     registryCredential = 'dockerhub'
   }
-  agent any
+  agent { label 'osm1' }
   stages {
     stage('Build API-FE image') {
       steps{