Changed `<Leader>a=` to only align one `=` sign
Changed `<Leader>a=` to only align one `=` sign

Currently `<Leader>a=` acting on the following:
````
a = b == 3
xyz = u == v
````
produces
````
a   = b = = 3
xyz = u = = v
````
.. which is probably not what the user intended.
Since aligning `=` almost always refers to assignment, it makes sense to only align the first one.
Acanthostega/spf13-vim