fix issues with shellcheck and shfmt

dnsapi/dns_azure.sh

@@ -316,8 +316,9 @@ _azure_getaccess_token() {
 
     if [ "$arc" = true ]; then
       response="$(_get http://localhost:40342/metadata/identity/oauth2/token\?api-version=2019-08-15\&resource=https://management.azure.com/)"
-    	T=$(cat $HTTP_HEADER | grep Www | sed 's/Www-Authenticate: Basic realm=//g' | sed 's/[^a-zA-Z0-9\/\.\-]//g')
-    	export _H2="Authorization: Basic $(cat $T)"
+      CHALLANGE=$(cat "$HTTP_HEADER" | grep Www | sed 's/Www-Authenticate: Basic realm=//g' | sed 's/[^a-zA-Z0-9\/\.\-]//g')
+      _H2="Authorization: Basic $(cat "$CHALLANGE")"
+      export _H2
       response="$(_get http://localhost:40342/metadata/identity/oauth2/token\?api-version=2019-08-15\&resource=https://management.azure.com/)"
     else
       response="$(_get http://169.254.169.254/metadata/identity/oauth2/token\?api-version=2018-02-01\&resource=https://management.azure.com/)"