IDB crashes once an application is selected

[prithiviraj]

IDB closes once an application is selected.

1. "Select App..." displays the current application
2. IDB closes after the application is selected. Below is the stack trace info received.

3: from /usr/local/lib/ruby/gems/2.5.0/gems/idb-2.10.3/lib/idb.rb:122:in block in init_ui' 2: from /usr/local/lib/ruby/gems/2.5.0/gems/idb-2.10.3/lib/gui/main_tab_widget.rb:163:in app_changed' 1: from /usr/local/lib/ruby/gems/2.5.0/gems/idb-2.10.3/lib/gui/app_tab_widget.rb:48:in app_changed' /usr/local/lib/ruby/gems/2.5.0/gems/idb-2.10.3/lib/gui/app_details_group_box.rb:69:in app_changed': undefined method `sub' for nil:NilClass (NoMethodError) recv failed: Resource temporarily unavailable

[andreykostakov]

Same here. Faced with problem on iPhone 5c 10.3.3 and iPhone 6s 10.3.3

[adaghma]

Same issue iPad 4 10.3.3

[mechanico]

see #105