Fix typo

Change-Id: I3c949642299cb1fde7133cf429b02d5d3ef0d7ed
Signed-off-by: Frederic Gurr <frederic.gurr@eclipse-foundation.org>
diff --git a/infoCenter/app/createInfoCenter.sh b/infoCenter/app/createInfoCenter.sh
index 43e9b58..2f80f42 100755
--- a/infoCenter/app/createInfoCenter.sh
+++ b/infoCenter/app/createInfoCenter.sh
@@ -109,7 +109,7 @@
 set -o nounset
 set -o pipefail
 
-p2_repo_dir=${1:}
+p2_repo_dir=${1:-}
 jar_list=$(find "${p2_repo_dir}/plugins" -name '*.jar' ! -name '*source*' -printf '%f\n')
 output_file="doc_plugins.tar"