kivy crash reporter: warn users not to share sensitive info

Previously only Qt had the warning.

electrum/base_crash_reporter.py

@@ -55,6 +55,8 @@ class BaseCrashReporter(Logger):
                              'useful debug information:')
     DESCRIBE_ERROR_MESSAGE = _("Please briefly describe what led to the error (optional):")
     ASK_CONFIRM_SEND = _("Do you want to send this report?")
+    USER_COMMENT_PLACEHOLDER = _("Do not enter sensitive/private information here. "
+                                 "The report will be visible on the public issue tracker.")
 
     def __init__(self, exctype, value, tb):
         Logger.__init__(self)

electrum/gui/kivy/uix/dialogs/crash_reporter.py

@@ -104,6 +104,7 @@ class CrashReporter(BaseCrashReporter, Factory.Popup):
         self.ids.crash_message.text = BaseCrashReporter.CRASH_MESSAGE
         self.ids.request_help_message.text = BaseCrashReporter.REQUEST_HELP_MESSAGE
         self.ids.describe_error_message.text = BaseCrashReporter.DESCRIBE_ERROR_MESSAGE
+        self.ids.user_message.hint_text = BaseCrashReporter.USER_COMMENT_PLACEHOLDER
 
     def show_contents(self):
         details = CrashReportDetails(self.get_report_string())

electrum/gui/qt/exception_window.py

@@ -77,8 +77,7 @@ class Exception_Window(BaseCrashReporter, QWidget, MessageBoxMixin, Logger):
 
         self.description_textfield = QTextEdit()
         self.description_textfield.setFixedHeight(50)
-        self.description_textfield.setPlaceholderText(_("Do not enter sensitive/private information here. "
-                                                        "The report will be visible on the public issue tracker."))
+        self.description_textfield.setPlaceholderText(self.USER_COMMENT_PLACEHOLDER)
         main_box.addWidget(self.description_textfield)
 
         main_box.addWidget(QLabel(BaseCrashReporter.ASK_CONFIRM_SEND))