Explanation:

Use of ‘I wish’ and ‘if’ together in a sentence makes it superfluous as both the expressions are used to express an unfulfilled wish/ desire/ condition. So, we need to eliminate ‘if’ from the given sentence. Also, we need to replace “was” with “were” because the rule says If certain expressions like unfulfilled wish / condition / desire in the present state is to be brought into expression – with the use of if / as if / as though / I wish / it is time / it is high time, etc. along with which ‘to be’ is used, then only its ‘were’ form is used provided whatever be the number and person of the subject.