[FIX] product: Two product.price.history created for one variant

When a unique variant was created from a product template with function create_variant_ids,
two product price history were created:

-One was created from function create on product.product
-The other one was created from function _set_standard_price on
product.template

The first product.price.history created in this situation was all the time
set to 0 and it lead to some problems in the report inventory date.
This first product.price.history doesn't have to be created.

opw:747857

addons/product/models/product.py

@@ -314,7 +314,9 @@ class ProductProduct(models.Model):
     @api.model
     def create(self, vals):
         product = super(ProductProduct, self.with_context(create_product_product=True)).create(vals)
-        product._set_standard_price(vals.get('standard_price', 0.0))
+        # When a unique variant is created from tmpl then the standard price is set by _set_standard_price
+        if not (self.env.context.get('create_from_tmpl') and len(product.product_tmpl_id.product_variant_ids) == 1):
+            product._set_standard_price(vals.get('standard_price') or 0.0)
         return product
 
     @api.multi

addons/product/models/product_template.py

@@ -264,7 +264,7 @@ class ProductTemplate(models.Model):
         tools.image_resize_images(vals)
         template = super(ProductTemplate, self).create(vals)
         if "create_product_product" not in self._context:
-            template.create_variant_ids()
+            template.with_context(create_from_tmpl=True).create_variant_ids()
 
         # This is needed to set given values to first variant after creation
         related_vals = {}