Fix init screen to use alert dialog

To initiate a local password-store, you
need a gpg-key, and now we can tell the user
as much

src/main.py

@@ -8,6 +8,7 @@ from typing import Union
 
 import wx
 import wx.lib.scrolledpanel as scrolled
+import wx.lib.dialogs as dialogs
 import gnupg
 
 from pass_handler import Pass, copy_to_clipboard, get_password_from_path, pass_pull, pass_push, run_command
@@ -104,15 +105,18 @@ class PassUi(wx.Frame):
         self.sizer.Add(gpg_btn, 0, wx.EXPAND)  # pylint: disable=no-member
         self.Bind(wx.EVT_BUTTON,
                   lambda event: self.gpg_button_clicked(), gpg_btn)
-        if self.gpg_key:
         init_btn: wx.Button = wx.Button(self.pnl, label="Init Local Password Store")
         git_btn: wx.Button = wx.Button(self.pnl, label="Clone Remote Password Store From Git")
         self.sizer.Add(init_btn, 0, wx.EXPAND)  # pylint: disable=no-member
         self.sizer.Add(git_btn, 0, wx.EXPAND)  # pylint: disable=no-member
         self.Bind(wx.EVT_BUTTON,
                   lambda event: self.git_button_clicked(), git_btn)
+        if self.gpg_key:
             self.Bind(wx.EVT_BUTTON,
                       lambda event: self.init_button_clicked(), init_btn)
+        else:
+            self.Bind(wx.EVT_BUTTON,
+                      lambda event: dialogs.alertDialog(message='You must select a GPG key'), init_btn)
 
     def add_push_pull(self):
         """add_push_pull."""