Simplify conditions a bit

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/accounts/views.py

@@ -455,23 +455,21 @@ def password(request):
 
     do_change = False
 
-    if request.user.has_usable_password():
-        if request.method == 'POST':
+    if not request.user.has_usable_password():
+        do_change = True
+        change_form = None
+    elif request.method == 'POST':
         change_form = PasswordChangeForm(request.POST)
         if change_form.is_valid():
             cur_password = change_form.cleaned_data['password']
-                if request.user.check_password(cur_password):
-                    do_change = True
-                else:
+            do_change = request.user.check_password(cur_password)
+            if not do_change:
                 messages.error(
                     request,
                     _('You have entered an invalid password.')
                 )
     else:
         change_form = PasswordChangeForm()
-    else:
-        do_change = True
-        change_form = None
 
     if request.method == 'POST':
         form = PasswordForm(request.POST)