Remove any stray socket files before creating new ones

apps/files_external/tests/env/start-amazons3-ceph.sh

@@ -33,6 +33,7 @@ fi;
 
 # create readiness notification socket
 notify_sock=$(readlink -f "$thisFolder"/dockerContainerCeph.$EXECUTOR_NUMBER.amazons3.sock)
+rm -f "$notify_sock" # in case an unfinished test left one behind
 mkfifo "$notify_sock"
 
 user=test

apps/files_external/tests/env/start-swift-ceph.sh

@@ -33,6 +33,7 @@ fi;
 
 # create readiness notification socket
 notify_sock=$(readlink -f "$thisFolder"/dockerContainerCeph.$EXECUTOR_NUMBER.swift.sock)
+rm -f "$notify_sock" # in case an unfinished test left one behind
 mkfifo "$notify_sock"
 
 port=5001