[#3199|Console] Fix UnicodeEncodeError in addstr

The following error was encountered by user:

   ...deluge/ui/console/modes/basemode.py, line 290, in add_string
       screen.addstr(row, col, string, color)
   UnicodeEncodeError: 'ascii' codec can't encode character...

The `add_str` method is defaulting to using the Python 2 ascii
encoding with a unicode string so use the encoding passed to the
function.

deluge/ui/console/modes/basemode.py

@@ -299,7 +299,7 @@ def add_string(
                 string = string[0:remaining_chrs]
 
         try:
-            screen.addstr(row, col, string, color)
+            screen.addstr(row, col, string.encode(encoding), color)
         except curses.error as ex:
             # Ignore exception for writing offscreen.
             pass

deluge/ui/console/modes/cmdline.py

@@ -548,7 +548,7 @@ class CmdLine(BaseMode, Commander):
                 # This is the last string so lets append some " " to it
                 s += ' ' * (self.cols - (col + strwidth(s)) - 1)
             try:
-                self.stdscr.addstr(row, col, s, color)
+                self.stdscr.addstr(row, col, s.encode(self.encoding), color)
             except curses.error:
                 pass