*.sh: use consistent indentation

Almost all of the shell scripts in the repository use tabs for
indentation (or have no indentation at all):

    $ git grep -Il '^\t' -- '*.sh' | wc -l
    19
    $ git grep -Il '^ ' -- '*.sh' | wc -l
    5
    $ git grep -IL '^[ \t]' -- '*.sh' | wc -l
    25

So do the same in the few shell scripts that currently use spaces for
indentation.

Except for the following file:

* platform/rpm/mkrpm.sh

Not sure if it's following a packaging-specific scheme, so just fix the
one indentation inconsistency in it and otherwise leave it as is for
now.

Command used to search for shell scripts using spaces for indentation:

    $ git grep -In '^ ' -- '*.sh'

1 files changed, 4 insertions, 4 deletions

diff --git a/contrib/gdb-firejail.sh b/contrib/gdb-firejail.sh
index b00cc65bc..032b031f0 100755
--- a/contrib/gdb-firejail.sh
+++ b/contrib/gdb-firejail.sh
@@ -13,11 +13,11 @@ set -x
 # setuid firejail process from the absolute beginning.
 
 if [ -z "${1##*/firejail}" ]; then
-    FIREJAIL=$1
+        FIREJAIL=$1
 else
-    # First argument is not named firejail, then add default unless environment
-    # variable already set.
-    set -- ${FIREJAIL:=$(command -v firejail)} "$@"
+        # First argument is not named firejail, then add default unless environment
+        # variable already set.
+        set -- ${FIREJAIL:=$(command -v firejail)} "$@"
 fi
 
 bash -c "kill -STOP \$\$; exec \"\$0\" \"\$@\"" "$@" &