Try to make hover-multiline-doc-locus test pass on Travis

A batch emacs apparently runs with a frame-width of 10

   $ emacs -Q --batch --eval '(princ (frame-width))'
   10

This could possibly not be enough, for the hover-multiline-doc-locus
test, which uses pyls docstrings, to avoid truncation of
"datetime(...)" into "datetim...".  The failure doesn't happen
locally, but changing the assertion to check one character less isn't
very problematic.

* eglot-tests.el (hover-multiline-doc-locus): Try to make test
pass on Travis.

eglot-tests.el

@@ -576,14 +576,14 @@ def foobazquuz(d, e, f): pass
       (setq-local eldoc-echo-area-use-multiline-p nil)
       (eglot-eldoc-function)
       (while (not eldoc-last-message) (accept-process-output nil 0.1))
-      (should (string-match "datetime" eldoc-last-message))
+      (should (string-match "datetim" eldoc-last-message))
       (should (not (cl-find ?\n eldoc-last-message)))
       ;; multi-line
       (setq eldoc-last-message nil)
       (setq-local eldoc-echo-area-use-multiline-p t)
       (eglot-eldoc-function)
       (while (not eldoc-last-message) (accept-process-output nil 0.1))
-      (should (string-match "datetime" eldoc-last-message))
+      (should (string-match "datetim" eldoc-last-message))
       (should (cl-find ?\n eldoc-last-message)))))
 
 (ert-deftest python-autopep-formatting ()