[Fix] Email addres unique key issue (#12450)

diff --git a/erpnext/selling/doctype/customer/customer.py b/erpnext/selling/doctype/customer/customer.py
index 9c2545b..6c9e450 100644
--- a/erpnext/selling/doctype/customer/customer.py
+++ b/erpnext/selling/doctype/customer/customer.py
@@ -66,7 +66,7 @@
 			self.create_lead_address_contact()
 
 	def create_primary_contact(self):
-		if not self.customer_primary_contact:
+		if not self.customer_primary_contact and not self.lead_name:
 			if self.mobile_no or self.email_id:
 				contact = make_contact(self)
 				self.db_set('customer_primary_contact', contact.name)