prevent installer from closing by pressing Enter

CleanFlashInstaller/InstallForm.Designer.cs

@@ -374,6 +374,7 @@ namespace CleanFlashInstaller {
             this.prevButton.Name = "prevButton";
             this.prevButton.Size = new System.Drawing.Size(138, 31);
             this.prevButton.TabIndex = 3;
+            this.prevButton.TabStop = false;
             this.prevButton.Text = "QUIT";
             this.prevButton.UseVisualStyleBackColor = false;
             this.prevButton.Click += new System.EventHandler(this.prevButton_Click);