Any fluid that comes from that hole could be rain water, or it could be brake fluid. It is on the outside of the hydraulic system.
If it is rain water, then that is normal. The hole is there to drain away rain water from the outside of the boot.
If it is hydraulic fluid, then the secondary seal inside the bore is not doing its job.
In if the latter, then something needs to be replaced. Fluid should not get past the secindary seal inside the bore. It is possible to get a service kit to replace the boot, the piston and the spring - but really, if fluid is getting out, then water is getting in, and the inside of the SMC bore will more than likely be corroded. Between us, on the forum, we have seen many examples where a service kit has not resulted in a fix for the problem. The best solution is to buy a new SMC, along with the washers for the banjo bolts (2 per banjo bolt that has to be undone) - they don't need to be Honda, you can buy them from motorcycle parts suppliers. I use copper ones and have had no issues with them for the last 120,000 miles in our salty wet road conditions. (There is an argument that says that copper/alloy create better conditions for 'galvanic' corrosion due to the different electrical properties of the two metals. In practice I have noted that the Honda alloy ones seem to corrode more readily from out salty winter roads - - but I do protect mine with eg ACF50). The service kit is part of the new SMC / caliper bracket and is already fitted, and greased. It is an easy replacement, but can be a bit messy and you will need to bleed the brakes afterwards - so you need non return bleed valves and plenty of brake fluid. I buy 2 litres to do this, as I like to flush the old fluid out before I remove anything.
The peace of mind that you get after doing this is worth far more than the SMC costs. Yours is a pre-2008 SMC. Make sure that you order the correct part. From 2008, the SMC changed - they are not interchangeable.