Fix Icon class name that could be 'undefined'
Fix Icon class name that could be 'undefined'

poupotte/cozy-emails,poupotte/cozy-emails,cozy/cozy-emails,aenario/cozy-emails,nono/cozy-emails,aenario/cozy-emails,cozy/cozy-emails,nono/cozy-emails,frankrousseau/cozy-emails,frankrousseau/cozy-emails,clochix/cozy-emails,clochix/cozy-emails