Oscilloscope: Add isStartingConnection timeout to avoid hangs when selected EmotiBit disappears

[produceconsumerobot]

Probably ~3-5 seconds would be good inside of https://github.com/EmotiBit/ofxEmotiBit/blob/master/src/EmotiBitWiFiHost.cpp#L233

isStartingConnection = false;
connectedEmotibitIp = "";

Testing

• Open Oscilloscope with EmotiBit in device list but not connected
• Press and hold EmotiBit reset button
• Quickly click to connect to EmotiBit in Oscilloscope before it grays out
• Oscilloscope will be frozen for 5 seconds
• After 5 seconds, the connection should time out and oscilloscope should unfreeze