fix: Lead Contact with blank first name via Customer (#21247)

diff --git a/erpnext/selling/doctype/customer/customer.py b/erpnext/selling/doctype/customer/customer.py
index 02667e8..50e719f 100644
--- a/erpnext/selling/doctype/customer/customer.py
+++ b/erpnext/selling/doctype/customer/customer.py
@@ -150,7 +150,7 @@
 						contact.save()
 
 			else:
-				lead.lead_name = lead.lead_name.split(" ")
+				lead.lead_name = lead.lead_name.lstrip().split(" ")
 				lead.first_name = lead.lead_name[0]
 				lead.last_name = " ".join(lead.lead_name[1:])