Remove the Vector::append overload that takes a Vector

Source/platform/network/FormDataBuilder.cpp

Index: Source/platform/network/FormDataBuilder.cpp
diff --git a/Source/platform/network/FormDataBuilder.cpp b/Source/platform/network/FormDataBuilder.cpp
index b79483903ccc44342cf778498d9ad673bbf2f85c..45b1af9da8ef986d54035b6103d8155636e78b34 100644
--- a/Source/platform/network/FormDataBuilder.cpp
+++ b/Source/platform/network/FormDataBuilder.cpp
@@ -136,7 +136,7 @@ Vector<char> FormDataBuilder::generateUniqueBoundaryString()
         randomBytes.append(alphaNumericEncodingMap[randomness & 0x3F]);
     }
 
-    boundary.append(randomBytes);
+    boundary.appendVector(randomBytes);
     boundary.append(0); // Add a 0 at the end so we can use this as a C-style string.
     return boundary;
 }