### Please describe the problem.
The web app fails with an Internal server error while adding a remote server on Windows.
ssh: createProcess: does not exist (No such file or directory)

### What steps will reproduce the problem?
Start the webapp, click add repository, select remote server, click check.

### What version of git-annex are you using? On what operating system?
Latest (as of 20141104) on Windows.

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log

[2014-11-04 12:42:27 ora solare Europa occidentale] main: starting assistant version 5.20141031-gbfac20c
Launching web browser on file://C:\Users\ltaglialegne\Documents\Annex\.git\annex\webapp.html
[2014-11-04 12:42:27 ora solare Europa occidentale] Cronner: You should enable consistency checking to protect your data. 
(scanning...) [2014-11-04 12:42:27 ora solare Europa occidentale] Watcher: Performing startup scan
(started...) recv: failed (No error)
recv: failed (No error)
recv: failed (No error)
recv: failed (No error)
04/Nov/2014:12:44:30 +0100 [Error#yesod-core] ssh: createProcess: does not exist (No such file or directory) @(yesod-core-1.2.19:Yesod.Core.Class.Yesod .\Yesod\Core\Class\Yesod.hs:503:5)
04/Nov/2014:12:44:50 +0100 [Error#yesod-core] ssh: createProcess: does not exist (No such file or directory) @(yesod-core-1.2.19:Yesod.Core.Class.Yesod .\Yesod\Core\Class\Yesod.hs:503:5)

# End of transcript or log.
"""]]
