Update EIP-5450: fix typo

Reported via ipsilon/eof#121

EIPS/eip-5450.md

@@ -94,7 +94,7 @@ For each instruction:
    1. **Check** if the instruction is present in the code (i.e. execution must not "fall off" the code).
    2. If the successor is reached via forwards jump or sequential flow from previous instruction:
       1. If the instruction does not have stack height bounds recorded (visited for the first time), record the instruction stack height bound as the value computed in 2.3.
-      2. Otherwise instruction was already visited (by previously seen forward jump). Update this instruction's recorded stack height bounds so that they contain the bounds computed in 2.3, i.e. `target_stack_min = min(target_stack_min, current_stack_min)` and `target_stack_max = max(target_stack_max, current_stack_min)`, where `(target_stack_min, target_stack_max)` are successor bounds and `(current_stack_min, current_stack_max)` are bounds computed in 2.3.
+      2. Otherwise instruction was already visited (by previously seen forward jump). Update this instruction's recorded stack height bounds so that they contain the bounds computed in 2.3, i.e. `target_stack_min = min(target_stack_min, current_stack_min)` and `target_stack_max = max(target_stack_max, current_stack_max)`, where `(target_stack_min, target_stack_max)` are successor bounds and `(current_stack_min, current_stack_max)` are bounds computed in 2.3.
    3. If the successor is reached via backwards jump, **check** if the recorded stack height bounds equal the value computed in 2.3. Validation fails if they are not equal, i.e. we see backwards jump to a different stack height.
 
 After all instructions are visited, determine the function maximum operand stack height: