cubicweb-bootstrap #3666756 upgrading from 0.4.1 to 0.5.0 [validation pending]

While upgrading an instance from cubicweb-bootstrap 0.4.1 to cubicweb-bootstrap 0.5.0 :

Upgrading the instance imagen
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[...]
File "/usr/share/cubicweb/cubes/bootstrap/views/__init__.py", line 53, in registration_callback
(BSHTMLHeader, basetemplates.HTMLHeader),
AttributeError: 'module' object has no attribute 'HTMLHeader'
instance imagen not upgraded: 'module' object has no attribute 'HTMLHeader'

priorityimportant
typebug
done in0.5.1
load left0.000
closed by#e51cfc397fc7 [import] avoid a crush on basetemplates.HTMLHeader (closes #3666756)
patch[import] avoid a crush on basetemplates.HTMLHeader (closes #3666756) [applied]