Took me a few minutes, but I finally found it out:

"One of the most frequently asked question about the Montreal Canadiens is where does the nickname "Habs" originate.

Legend wants it that the "H" on the Canadiens logo stands for "Habs" instead of Club de Hockey Canadien. The fable began in 1924 when US reporter Tex Rickard was falsely informed by someone that the "H" stood for "habitant", a french word that in those days was used to refer the farmers of Quebec.

Rickard was told that the french players on the team came from farms and were therefore, "habitants". At the time, the Canadiens were viewed upon as the french team of Montreal, whereas the Montreal Maroons were the english team.

While the nickname "Habs" resulted from this disinformation to Rickard, the "H" in the logo has always stood for Hockey, it is taken from the club's official name "Club de Hockey Canadien". The Canadiens are also referred to as "Les Tricolores" (the team with three colours), "Les Glorieux" (The Glorious Ones), and "La Sainte Flanelle" (The Holy Flannel)."