[Code formatting: Change indentation style to space](https://github.com/clicon/clixon/issues/379)

* Applies to all c/h/y/l/sh files and .editorconfig

test/test_perf_restconf_ssl.sh

@@ -112,7 +112,7 @@ if [ $BE -ne 0 ]; then
     new "kill old backend"
     sudo clixon_backend -zf $cfg
     if [ $? -ne 0 ]; then
-	err
+        err
     fi
 
 #    sudo pkill clixon_backend # extra
@@ -172,7 +172,7 @@ ret=$(diff -i $ftest $foutput)
 if [ $? -ne 0 ]; then
     echo "diff -i $ftest $foutput"
     err1 "Matching running-db with $fdataxml"
-fi	
+fi      
 
 # RESTCONF get
 new "restconf get $perfreq small config 1 key index"
@@ -249,7 +249,7 @@ if [ $BE -ne 0 ]; then
     # Check if premature kill
     pid=$(pgrep -u root -f clixon_backend)
     if [ -z "$pid" ]; then
-	err "backend already dead"
+        err "backend already dead"
     fi
     # kill backend
     stop_backend -f $cfg