ReplaceGuardClause inspection: do not remove 'else' branch

#KT-32797 Fixed

idea/testData/inspectionsLocal/replaceGuardClauseWithFunctionCall/requireNotNull/hasElse.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(foo: Int?) {
+    <caret>if (foo == null) throw IllegalArgumentException("test") else println(1)
+}

idea/testData/inspectionsLocal/replaceGuardClauseWithFunctionCall/requireNotNull/hasElse.kt.after

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+fun test(foo: Int?) {
+    <caret>requireNotNull(foo) { "test" }
+    println(1)
+}