Update cpp/common/test/rules/unusedparameter/test.cpp

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: mbaluda

cpp/common/test/rules/unusedparameter/test.cpp

@@ -17,7 +17,7 @@ class A {
   void c(int) {}             // COMPLIANT
 
   // This is a violation of Rule 0-2-2, and therefore flagged by the default
-  // logic. However, this allowed by additional exception in A0-1-4. See A0-1-4
+  // logic. However, this is allowed by additional exception in A0-1-4. See A0-1-4
   // and Rule 0-2-2 tests for full coverage.
   virtual void d(int x, int y) {} // NON_COMPLIANT
 };