`t-if=""` generates invalid javascript when compiling the template

[LucasLefevre]

t-if="" generates code which is not valid javascript.

it generates code which looks like

"""
if () {
   // ...
}
"""

It crashes when owl tries to compile the code Error: Failed to compile template "Root": Unexpected token ')'

The error message isn't very helpful to debug/fix the xml template, especially if the template is quite large and the generated code is also big.

class Root extends Component {
    static components = {};
    static template = "Root"
}

<templates>
  <t t-name="Root">
    <div t-if="">Hi!</div>
  </t>
</templates>

:point_right: Playground

[ged-odoo]

yeah, seems like we could improve this...