Adapt sh-to-mod path-like env var parsing for Fish 4.3

Path-like environment variable are now printed by `set -xgL` as:
PATH '/usr/bin' '/home/user/.local/bin'
instead of:
PATH '/usr/bin'  '/home/user/.local/bin'

Double space changed into a single space separator.

Signed-off-by: Xavier Delaruelle <xavier.delaruelle@cea.fr>

Author: xdelaruelle

NEWS.rst

@@ -34,6 +34,8 @@ Modules 5.7.0 (not yet released)
   current Modules version against an installed version of Lmod.
 * Update the :subcmd:`sh-to-mod` mechanism to correctly parse shell alias on
   Dash shell version 0.5.13.
+* Update the :subcmd:`sh-to-mod` mechanism to correctly parse path-like
+  environment variable on Fish shell version 4.3.
 
 
 .. _5.6 release notes:

tcl/mfcmd.tcl

@@ -1496,7 +1496,7 @@ proc execShAndGetEnv {elt_ignored_list shell script args} {
             )?([^-]\S+)(.*?)$}
          set comprevar [list match valpart1 name valpart2]
          # translate back fish-specific code
-         set varvalmap [list {'  '} : {\'} ' {\"} \" \\\\ \\]
+         set varvalmap [list {'  '} : {' '} : {\'} ' {\"} \" \\\\ \\]
          set alvalmap [list { $argv;} {}]
 
          # fish builtins change LS_COLORS variable