Update WSL.ps1

Author: kousu

scripts/WSL.ps1

@@ -23,7 +23,7 @@ if ($LASTEXITCODE -ne 0) { throw "Could not install distro." }
 #   https://github.com/microsoft/WSL-DistroLauncher/blob/2ed9a9335fc89a688a5150c95eff4fbdbc830f25/DistroLauncher/DistributionInfo.cpp#L8-L33
 wsl -d Ubuntu-18.04 -u root useradd -m "$username"
 if ($LASTEXITCODE -ne 0) { throw }
-wsl -d Ubuntu-18.04 -u root sh -c "echo "${username}:${password}`n" | chpasswd" # wrapped in sh -c to get the pipe to work
+wsl -d Ubuntu-18.04 -u root sh -c 'echo "${username}:${password}" | chpasswd' # wrapped in sh -c to get the pipe to work
 if ($LASTEXITCODE -ne 0) { throw }
 wsl -d Ubuntu-18.04 -u root  chsh -s /bin/bash "$username"
 if ($LASTEXITCODE -ne 0) { throw }