fixed null pointer

src/eu/siacs/conversations/xml/TagWriter.java

@@ -75,4 +75,8 @@ public class TagWriter {
 	public boolean finished() {
 		return (this.writeQueue.size() == 0);
 	}
+
+	public boolean isActive() {
+		return outputStream != null;
+	}
 }

src/eu/siacs/conversations/xmpp/XmppConnection.java

@@ -678,6 +678,7 @@ public class XmppConnection implements Runnable {
 	public void sendIqPacket(IqPacket packet, OnIqPacketReceived callback) {
 		String id = nextRandomId();
 		packet.setAttribute("id", id);
+		packet.setFrom(account.getFullJid());
 		this.sendPacket(packet, callback);
 	}
 
@@ -761,12 +762,14 @@ public class XmppConnection implements Runnable {
 				socket.close();
 				return;
 		}
+		if (tagWriter.isActive()) {
 			tagWriter.finish();
 			while(!tagWriter.finished()) {
 				//Log.d(LOGTAG,"not yet finished");
 				Thread.sleep(100);
 			}
 			tagWriter.writeTag(Tag.end("stream:stream"));
+		}
 		} catch (IOException e) {
 			Log.d(LOGTAG,"io exception during disconnect");
 		} catch (InterruptedException e) {