gnu: Remove module imports from the host Guile.

These imports are incorrect and would trigger a warning since
f650dc0d80.

* gnu/packages/display-managers.scm (guix-simplyblack-sddm-theme)[arguments]:
Remove (srfi srfi-26) from #:modules.
* gnu/packages/fonts.scm (font-meslo-lg)[arguments]: Remove (ice-9 ftw)
from #:modules.
* gnu/packages/ssh.scm (hpn-ssh)[arguments]: Remove (ice-9 string-fun)
from #:imported-modules.
* gnu/packages/tls.scm (dehydrated)[arguments]: Remove (srfi srfi-26)
from #:modules.

Change-Id: Ib712f9f1df62e65adfb685a3a37f1c53a22acad0
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/display-managers.scm

@@ -237,8 +237,7 @@ blurred background.")
         (base32 "09vb9b0pmyhj6fh0b6by59bykszbkdayhz678pnb4pyrdmlvv1am"))))
     (build-system trivial-build-system)
     (arguments
-     `(#:modules ((guix build utils)
-                  (srfi srfi-26))
+     `(#:modules ((guix build utils))
        #:builder (begin
                    (use-modules (guix build utils)
                                 (srfi srfi-26))

gnu/packages/fonts.scm

@@ -4206,8 +4206,7 @@ characteristic so that they sit smoothly with the Tamil glyphs.")
        (base32 "1594lxdk6788bb3i3c2fh74z4pwpzcp2r1xl3cz8cz77nrcjkl8m"))))
     (build-system trivial-build-system)
     (arguments
-     (list #:modules '((guix build utils)
-                       (ice-9 ftw))
+     (list #:modules '((guix build utils))
            #:builder
            #~(let* ((orig #$(package-source this-package))
                     (dist (string-append orig "/dist/v" #$version))

gnu/packages/ssh.scm

@@ -381,8 +381,6 @@ Additionally, various channel-specific options can be negotiated.")
                  #$flags))
        ((#:modules mods %default-gnu-modules)
         (cons '(ice-9 string-fun) mods))
-       ((#:imported-modules mods %default-gnu-imported-modules)
-        (cons '(ice-9 string-fun) mods))
        ((#:phases phases #~(list))
         #~(modify-phases #$phases
             (add-after 'unpack 'patch-ssh-stuff

gnu/packages/tls.scm

@@ -1037,8 +1037,7 @@ coding footprint.")
     (build-system trivial-build-system)
     (arguments
      (list
-      #:modules '((guix build utils)
-                  (srfi srfi-26))
+      #:modules '((guix build utils))
       #:builder
       #~(begin
           (use-modules (guix build utils)