[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_netconf.sh

@@ -80,7 +80,7 @@ if [ $BE -ne 0 ]; then
     new "kill old backend"
     sudo clixon_backend -zf $cfg
     if [ $? -ne 0 ]; then
-	err
+        err
     fi
 
     new "start backend -s init -f $cfg -- -s"
@@ -135,7 +135,7 @@ echo "$(chunked_framing "$rpc")" >> $ftest
 ret=$(diff $ftest $foutput)
 if [ $? -ne 0 ]; then
     err1 "Matching running-db with $fconfigonly"
-fi	
+fi      
 
 # Now commit it again from candidate (validation takes time when
 # comparing to existing)
@@ -234,7 +234,7 @@ 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