view: Fix focus index before and after Panel Search.

This commit corrects what the code for focus_index_before_search was
intended to do. The focus index was still being updated even in the
search results.

This is fixed by moving `get_focus` into the SEARCH_STREAM/TOPIC
conditional.

Fixes zulip#975

Author: Rohitth007

zulipterminal/ui_tools/views.py

@@ -367,6 +367,7 @@ def mouse_event(
 
     def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
         if is_command_key("SEARCH_STREAMS", key):
+            _, self.focus_index_before_search = self.log.get_focus()
             self.set_focus("header")
             return key
         elif is_command_key("GO_BACK", key):
@@ -377,9 +378,7 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
             self.log.set_focus(self.focus_index_before_search)
             self.view.controller.update_screen()
             return key
-        return_value = super().keypress(size, key)
-        _, self.focus_index_before_search = self.log.get_focus()
-        return return_value
+        return super().keypress(size, key)
 
 
 class TopicsView(urwid.Frame):
@@ -482,6 +481,7 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
             self.view.show_left_panel(visible=False)
             self.view.body.focus_col = 1
         if is_command_key("SEARCH_TOPICS", key):
+            _, self.focus_index_before_search = self.log.get_focus()
             self.set_focus("header")
             self.header_list.set_focus(2)
             return key
@@ -493,9 +493,7 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
             self.log.set_focus(self.focus_index_before_search)
             self.view.controller.update_screen()
             return key
-        return_value = super().keypress(size, key)
-        _, self.focus_index_before_search = self.log.get_focus()
-        return return_value
+        return super().keypress(size, key)
 
 
 class UsersView(urwid.ListBox):