show "n/a" instead of null when connection name is not available

Author: PhilippSalvisberg

sqldev/src/main/java/org/utplsql/sqldev/model/runner/Run.java

@@ -78,7 +78,7 @@ public void setStartTime(final String startTime) {
 
     public String getName() {
         final String time = startTime.substring(11, 19);
-        final String conn = connectionName != null ? connectionName.substring(15) : null;
+        final String conn = connectionName != null ? connectionName.substring(15) : "n/a";
         final StringBuilder sb = new StringBuilder();
         sb.append(time);
         sb.append(" (");