tvbrowser: fix shell indentation in test derivation

pkgs/applications/misc/tvbrowser/test.nix

···
     runtimeInputs = [ xorg.xwininfo tvbrowser ];
     text = ''
       function find_tvbrowser_windows {
-          for window_name in java tvbrowser-TVBrowser 'Setup assistant' ; do
-              grep -q "$window_name" "$1"  ||  return 1
-          done
+        for window_name in java tvbrowser-TVBrowser 'Setup assistant' ; do
+          grep -q "$window_name" "$1"  ||  return 1
+        done
       }
       tvbrowser &
       for _ in {0..900} ; do
-          xwininfo -root -tree  \
-              | sed 's/.*0x[0-9a-f]* \"\([^\"]*\)\".*/\1/; t; d'  \
-              | tee window-names
-          echo
-          if find_tvbrowser_windows window-names ; then
-              break
-          fi
-          sleep 1
+        xwininfo -root -tree  \
+            | sed 's/.*0x[0-9a-f]* \"\([^\"]*\)\".*/\1/; t; d'  \
+            | tee window-names
+        echo
+        if find_tvbrowser_windows window-names ; then
+          break
+        fi
+        sleep 1
       done
       find_tvbrowser_windows window-names
     '';