fix the channel name

Author: nandajavarma

.werft/jobs/build/self-hosted-upgrade-tests.ts

@@ -69,9 +69,11 @@ export async function triggerUpgradeTests(werft: Werft, config: JobConfig, usern
 }
 
 export async function triggerSelfHostedPreview(werft: Werft, config: JobConfig, username: string) {
-    const replicatedChannel =  config.replicatedChannel || config.repository.branch;
+    const channel =  config.replicatedChannel || config.repository.branch;
     const cluster =  config.cluster || "k3s";
 
+    const replicatedChannel = channel.replace("/", "-")
+
     exec(`git config --global user.name "${username}"`);
     var annotation = `-a channel=${replicatedChannel} -a preview=true -a skipTests=true -a deps=external`;