org-bbdb: Wrap defvar org-bbdb-old in eval-after-load

* org-bbdb.el (org-bbdb-old): Wrap `defvar' so the variable gets
  defined after bbdb was loaded.

Thanks to Nick Dokos for reporting this glitch in
<8273.1330161610@alphaville>.

lisp/org-bbdb.el

@@ -119,7 +119,8 @@
 (defvar date)   ;; dynamically scoped from Org
 
 ;; Support for version 2.35
-(defvar org-bbdb-old (fboundp 'bbdb-record-get-field-internal))
+(eval-after-load 'bbdb
+  '(defvar org-bbdb-old (fboundp 'bbdb-record-get-field-internal)))
 
 ;; Customization