Disable completions commands

Reviewed By: velocityboy

Differential Revision: D9920473

fbshipit-source-id: d780e1c289ea49776825cfb42f4515b7e652f096

Author: ebluestein

pkg/nuclide-debugger-hhvm-rpc/lib/hhvmDebugger.js

@@ -370,7 +370,7 @@ class HHVMDebuggerWrapper {
               supportsRestartRequest: false,
               supportsConditionalBreakpoints: true,
               supportsStepBack: false,
-              supportsCompletionsRequest: true,
+              supportsCompletionsRequest: false,
               supportsRestartFrame: false,
               supportsStepInTargetsRequest: false,
               supportsFunctionBreakpoints: true,
@@ -418,6 +418,9 @@ class HHVMDebuggerWrapper {
           this._asyncBreakPending = true;
           return false;
         }
+        case 'completions': {
+          return true;
+        }
         default:
           break;
       }