Minor grammar correction for ECMA-424 (#717)

Reviewed by Aki

Author: stevespringett

schema/bom-1.7.schema.json

@@ -1079,7 +1079,7 @@
             "ancestors": {
               "type": "array",
               "title": "Ancestors",
-              "description": "Describes zero or more components in which a component is derived from. This is commonly used to describe forks from existing projects where the forked version contains a ancestor node containing the original component it was forked from. For example, Component A is the original component. Component B is the component being used and documented in the BOM. However, Component B contains a pedigree node with a single ancestor documenting Component A - the original component from which Component B is derived from.",
+              "description": "Describes zero or more components in which a component is derived from. This is commonly used to describe forks from existing projects where the forked version contains an ancestor node containing the original component it was forked from. For example, Component A is the original component. Component B is the component being used and documented in the BOM. However, Component B contains a pedigree node with a single ancestor documenting Component A - the original component from which Component B is derived from.",
               "items": {"$ref": "#/definitions/component"}
             },
             "descendants": {