shell: show banner only once

Signed-off-by: Joel Fernandes <joel@joelfernandes.org>
diff --git a/addons/bashrc b/addons/bashrc
index 8c25c22..14b9253 100644
--- a/addons/bashrc
+++ b/addons/bashrc
@@ -1,6 +1,8 @@
 # The bannered bashrc
 source .bashrc.common
 
+if [ ! -f .banner.shown ]; then
+
 echo ""
 echo "##########################################################"
 echo "# Welcome to androdeb environment running on Android!    #"
@@ -14,4 +16,6 @@
 echo "##########################################################"
 echo ""
 
+touch .banner.shown
 
+fi