Multi-line command substitution does not work

[steinybot]

Description

A multi-line command substitution is not escaped.

Versions

Component	Version
Zsh Escape	3fe0017
OS	Windows 10
Zsh	zsh 5.0.6 (i686-pc-cygwin)

Steps To Reproduce

Steps to reproduce the bug:

1. Use the following file bad-script.zsh:

    ref=$(abc \
	    || def)

2. Run:

zsh-escape.zsh report -d bad-script.zsh

Expected Behaviour

The report finds the start and the end of the command substitution (and fix can escape it).

1 :     ref=$(abc \
DEBUG: Start of command substitution
- Unescaped substitution: $(abc \
- Found an unescaped command substitution
2 : 	    || def)
DEBUG: End of command substitution
- Unescaped substitution: 	    || def)

Actual Behaviour

It thinks that there is a variable with no name.

1 :     ref=$(abc \
- Unescaped variable: $
- Found an unescaped variable
2 : 	    || def)