doc: correct command formatting

Leaving spaces around the `-delimeters for commands means asciidoc fails
to parse them as the start of a literal string.  Remove an extraneous
space that is causing a literal to not be formatted as such.

Signed-off-by: Adam Dinwoodie <adam@dinwoodie.org>
Acked-by: Andreas Heiduk <asheiduk@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git.txt

@@ -75,7 +75,7 @@ example the following invocations are equivalent:
 Note that omitting the `=` in `git -c foo.bar ...` is allowed and sets
 `foo.bar` to the boolean true value (just like `[foo]bar` would in a
 config file). Including the equals but with an empty value (like `git -c
-foo.bar= ...`) sets `foo.bar` to the empty string which ` git config
+foo.bar= ...`) sets `foo.bar` to the empty string which `git config
 --bool` will convert to `false`.
 
 --exec-path[=<path>]::