sql: Reduce maximal trigger call chain

LLVM is more eager for frame size than GCC
Current maximal call chain length may corrupt stack then.
Reduce maximal call chain length to 30.

Related to #2550

src/box/sql/sqliteLimit.h

@@ -219,4 +219,4 @@
 ** number of entities (in chain of compiling trigger programs) should be less than
 ** 40 or stack guard will be triggered.
 */
-#define SQL_MAX_COMPILING_TRIGGERS 40
+#define SQL_MAX_COMPILING_TRIGGERS 30

test/sql-tap/trigger-chain-limit.test.lua

@@ -2,7 +2,7 @@
 test = require("sqltester")
 test:plan(8)
 
-for _, table_count in ipairs({40, 41}) do
+for _, table_count in ipairs({30, 31}) do
     -- Clean up, create tables, add entries
     for i = 1,table_count do
         -- First table for uniform triggers check