Is a resistor required to power a LED strip with a 9V battery?
The typical 12V strip has a voltage range of 10 to 14 volts. Less than 10 and they barely light. The leds alone  have a forward voltage of 3.6V at their typical nominal forward current, so you add in the voltage drop across the resistor, and 9V won't cut it.

You could short out the resistor as suggested and connect the 9V battery. It's internal equivalent series resistance and the lower voltage will light the leds at less than normal brightness. Unfortunately a 9V battery has low capacity and won't last long. Slightly better, you can short 1 led, and add a resistor in series. The resistor should be (Vs - Vf) / If = R1 + R2, where r1 is the existing resistor, vs is voltage source 9V, and Vf is 3.6 times 2 for 2 leds. If may be 0.06 A or 60mA for those leds. This would last a little longer. 

If you want 5 of these in parallel, your 9V battery ain't going to last half an hour...

Instead, get 5V led strips, and a usb power bank. Rechargeable, no resistors needed. Just an old usb cable.