[bugfix] Do not strip all whitespaces from title

Bug: T197642
Change-Id: Ia482218cc569e566dbd8bfd0927a469667e0a26c
---
M pywikibot/page/__init__.py
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pywikibot/page/__init__.py b/pywikibot/page/__init__.py
index fdc1973..4142102 100644
--- a/pywikibot/page/__init__.py
+++ b/pywikibot/page/__init__.py
@@ -5988,9 +5988,9 @@
 
         # "empty" local links can only be self-links
         # with a fragment identifier.
-        if not t.strip() and not self._is_interwiki:
-            raise pywikibot.InvalidTitle('The link does not contain a page '
-                                         'title')
+        if not t.strip(' ') and not self._is_interwiki:  # T197642
+            raise pywikibot.InvalidTitle(
+                'The link does not contain a page title')
 
         if self._site.namespaces[self._namespace].case == 'first-letter':
             t = first_upper(t)

