correct comment mistake

Ideally this should be constexpr, but this is C99, not C++17...

Author: NattyNarwhal

ibm_db2.c

@@ -2368,7 +2368,7 @@ static int _php_db2_connect_helper( INTERNAL_FUNCTION_PARAMETERS, conn_handle **
         /* Check if we already have a connection for this userID & database combination */
         if (isPersistent) {
             zend_resource *entry;
-            /* 17 = strlen("FFFFFFFF") strlen("__db2_") + strlen('.') + strlen(".") + null */
+            /* 17 = strlen("FFFFFFFF") + strlen("__db2_") + strlen(".") + strlen(".") + null */
             hKeyLen = strlen(database) + strlen(uid) + 17;
             hKey = (char *) ecalloc(1, hKeyLen);