Actually, SR44s (silver-oxide 1,55 V) will be better for it. Not only, because they will last longer (ca. 200-210 mAh versus 150-160 mAh for the common LR44s), but also because silver-oxide batteries have a more constant discharge curve compared to their alkaline brothers. The metering circuit will easily deal with the little extra voltage.

I routinely use SR44s where LR44s were specified, no problem.

EDIT: I just looked this up and Leica actually suggest using SR44 batteries and not LR44 in the manual.