handle >1 plugins to be installed with dependencies

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>
diff --git a/Dockerfile b/Dockerfile
index 20a6d54..3617254 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -62,4 +62,4 @@
 
 # from a derived Dockerfile, can use `RUN plugins.sh active.txt` to setup /usr/share/jenkins/ref/plugins from a support bundle
 COPY plugins.sh /usr/local/bin/plugins.sh
-COPY install-plugin.sh /usr/local/bin/install-plugin.sh
+COPY install-plugins.sh /usr/local/bin/install-plugins.sh