Index: trunk/src/org/openstreetmap/josm/tools/Http1Client.java
===================================================================
--- trunk/src/org/openstreetmap/josm/tools/Http1Client.java	(revision 15673)
+++ trunk/src/org/openstreetmap/josm/tools/Http1Client.java	(revision 15674)
@@ -75,5 +75,9 @@
     @Override
     protected ConnectionResponse performConnection() throws IOException {
-        connection.connect();
+        try {
+            connection.connect();
+        } catch (RuntimeException e) {
+            throw new IOException(e);
+        }
         return new ConnectionResponse() {
             @Override