Fix testing a 8-bit integer instead of a 32-bit integer in PSL library

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/2002

The code was testing only the LSB of a 32-bit integer to detect
whether the current rule was a wildcard (`*`), while it had to
compare against the whole 32-bit integer.

The breakage occurred when the LSB of an offset to the character
buffer happened to match the ASCII code of `*` (42, 0x2A).

(An offset is used when a label is longer than 4 characters)

src/lib/publicsuffixlist/publicsuffixlist.js

@@ -403,7 +403,7 @@ const getPublicSuffixPosJS = function() {
         }
         // 2. If no rules match, the prevailing rule is "*".
         if ( iFound === 0 ) {
-            if ( buf8[iCandidates + 1 << 2] !== 0x2A /* '*' */ ) { break; }
+            if ( buf8[iCandidates + 1] !== 0x2A /* '*' */ ) { break; }
             buf8[SUFFIX_NOT_FOUND_SLOT] = 1;
             iFound = iCandidates;
         }

src/lib/publicsuffixlist/wasm/publicsuffixlist.wat

@@ -255,7 +255,7 @@
         i32.eqz
         if
             get_local $iCandidates
-            i32.load8_u offset=4
+            i32.load offset=4
             i32.const 0x2A
             i32.ne
             br_if $labelLookupDone