Replaced mentions of Instance with Security Center

doc/user/application_security/vulnerability_report/index.md

@@ -8,7 +8,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 # Vulnerability Report **(ULTIMATE)**
 
 The Vulnerability Report provides information about vulnerabilities from scans of the branch most
-recently merged into the default branch. It is available at the instance, group, and project level.
+recently merged into the default branch. It is available for groups, projects, and the Security Center.
 
 At all levels, the Vulnerability Report contains:
 
@@ -73,7 +73,7 @@ The content of the Project filter depends on the current level:
 
 | Level          | Content of the Project filter |
 |:---------------|:------------------------------|
-| Instance level | Only projects you've [added to the instance-level Security Center](../security_dashboard/index.md#adding-projects-to-the-security-center). |
+| Security Center | Only projects you've [added to your personal Security Center](../security_dashboard/index.md#adding-projects-to-the-security-center). |
 | Group level    | All projects in the group. |
 | Project level  | Not applicable. |