Simplify confusing and error-provoking context conditionals in executionContextChange

src/execution-context.js

@@ -128,24 +128,28 @@ function ExecutionContext () {
       })
     }
 
-    if (context === 'web3') {
-      modalDialogCustom.confirm(null, 'Are you sure you want to connect to an ethereum node?',
-        () => { runPrompt(endPointUrl) }, () => { cb() }
-      )
-    } else if (context === 'injected' && injectedProvider === undefined) {
-      cb()
-    } else {
-      if (context === 'injected') {
-        executionContext = context
-        web3.setProvider(injectedProvider)
-        self.event.trigger('contextChanged', ['injected'])
-      } else if (context === 'vm') {
+    if (context === 'vm') {
       executionContext = context
       vm.stateManager.revert(function () {
         vm.stateManager.checkpoint()
       })
       self.event.trigger('contextChanged', ['vm'])
     }
+
+    if (context === 'injected') {
+      if (injectedProvider === undefined) {
+        cb()
+      } else {
+        executionContext = context
+        web3.setProvider(injectedProvider)
+        self.event.trigger('contextChanged', ['injected'])
+      }
+    }
+
+    if (context === 'web3') {
+      modalDialogCustom.confirm(null, 'Are you sure you want to connect to an ethereum node?',
+        () => { runPrompt(endPointUrl) }, () => { cb() }
+      )
     }
   }